Dna encoding a cholecystokinin receptor

ABSTRACT

An unconventional approach to purifying CCK receptor protein to sequenceable-grade homogeneity has been discovered. By this approach, CCK receptor protein can be obtained and sequenced routinely from a variety sources, and from the sequence information thus obtained it is possible to prepare oligonucleotides suitable for cloning CCK receptor genes. “CCK receptor” in this context denotes any from a group of proteins that displays a characteristic CCK binding affinity and that is encoded by a nucleotide sequence which hybridizes a oligonucleotide probe designed in accordance with the criteria elaborated herein.

[0001] The present application is a continuation in part of U.S. application Ser. No. 07/831,248, filed Feb. 7, 1992, and now abandoned, of Ser. No. 07/861,769, filed Apr. 1, 1992, of Ser. No. 07/928,033, filed Aug. 11, 1992, and of Ser. No. 07/937,609, filed Sep. 2, 1992.

BACKGROUND OF THE INVENTION

[0002] The present invention relates to the purification of cholecystokinin (CCK) receptor protein to sequenceable-grade homogeneity. The present invention further relates to obtaining and expressing DNAs that code for CCK receptor protein.

[0003] A family of cholecystokinin peptides was originally isolated from the mammalian gastrointestinal tract and was one of the first gastrointestinal peptides to be discovered in the brain. The predominant molecular form of CCK peptide is cholecystokinin-octapeptide (CCK-8) which exists in a sulfated and non-sulfated form.

[0004] The cholecystokinin family of receptors is widely distributed throughout the gastrointestinal and central nervous systems where they regulate pancreatic and gastric secretion, smooth muscle motility, growth, anxiety and satiety, analgesia and neuroleptic activity. The receptor family includes CCK_(A) and CCK_(B)/gastrin receptors by virtue of their affinity for a structurally and functionally related family of peptides, including CCK and CCK analogues having identical COOH terminal pentapeptide sequence and varying sulfation at the sixth (gastrin) and seventh (CCK) tyrosyl residues. CCK_(B) receptors more recently have been designated CCK_(B)/gastrin receptors because of the suspected homology, perhaps even identity, between CCK_(B) and gastrin receptors. Kopin et al., PNAS USA 89: 3605 (1992).

[0005] Recently, nonpeptide agonists highly selective for each of the CCK receptor subtypes have been developed and further support the subtype classification. The most potent and selective antagonists are L-364,718 for CCK_(A) and L-365,260 and PD134408 for CCK_(B)/gastrin receptors. The CCK_(A) receptor differs from CCK_(B)/gastrin receptor particularly in its selectivity for CCK peptide analogues with a sulfate at the seventh position from the COOH terminus.

[0006] The CCK_(A) receptor mediates physiologic gallbladder contraction, pancreatic growth and enzyme secretion, delayed gastric emptying, relaxation of the sphincter of Oddi and potentiation of insulin secretion. The CCK_(A) receptor also appears in the anterior pituitary, in the myenteric plexus, and in areas of the CNS (midbrain) where CCK interaction with dopaminergic neurons has been implicated in the pathogenesis of a schizophrenia, Parkinson's disease, drug addiction and feeding disorders. Experimental rat pancreatic carcinogenesis is promoted by CCK through the CCK_(A) receptor.

[0007] CCK_(A) receptors in pancreatic acinar cells have been most well characterized because of the ability to prepare a homogeneous preparation of a hormonally responsive effector system in dispersed acini. In pancreatic acinar cells, CCK peptide interacts specifically with its cell surface receptor, which is coupled to a guanine nucleotide regulatory protein (G protein) which activates phospholipase C, the breakdown of phosphoinositides, the mobilization of intracellular calcium, and the activation of protein kinase C.

[0008] CCK_(A) receptors have been functionally expressed in the plasma membrane of oocytes after injection of rat brain total RNA, and of mRNA from rat pancreatic acinar carcinoma cell line, AR42J. Affinity labeling studies of CCK_(A) receptors from rat pancreas and partial purification demonstrate an 85-95 kDa, heavily glycosylated, binding subunit with a deglycosylated core protein of 42 kDa.

[0009] The CCK_(B)/gastrin receptor is found predominantly throughout the CNS, where it is thought to modulate anxiety and neuroleptic activity. Interaction between CCK peptide and CCK_(B)/gastrin receptors on mesocorticolimbic, dopaminergic neurons influences the physiological states of stress and anxiety. The presence of CCK_(B)/gastrin receptors on peripheral monocytes and monocyte-derived splenic cells suggests that CCK plays a role in the long suspected neuroendocrine modulation of the immune system.

[0010] CCK_(B)/gastrin receptors, found on gastric parietal and chief cells, and gastrointestinal smooth muscle cells, regulate acid and pepsinogen secretion, and gastrointestinal motility, respectively. They are also present on some human gastric and colon cancer cells where they may regulate growth. CCK peptide, acting at peripheral CCK_(A) receptors and at central CCK_(A) and CCK_(B)/gastrin receptors plays a significant role in the nervous system control of appetite.

[0011] Attempts have been made to purify CCK receptor protein to homogeneity, but these efforts were unsuccessful. Duong et al., J. Biol. Chem. 264: 17990-96 (1989), used digitonin-solubilized rat pancreatic receptor to obtain a receptor preparation estimated to be of 80% purity. The Duong purification scheme included a three-step purification process utilizing cation exchange, Ulex europaeus agglutinin-I-agarose, and Sephacryl S-300. Szecowka et al., Regulatory Peptides 24: 215-24 (1989), employed a two-step purification scheme to partially purify digitonin-solubilized rat pancreatic receptor that included lectin and CCK affinity chromatography.

[0012] Researchers labored unsuccessfully for years to illuminate the molecular structure of CCK receptor protein, but were limited by the inability to purify receptor protein to a homogeneity sufficient for sequencing purposes. Instead, attempts to obtain a purified preparation yielded a partially purified CCK receptor, along with non-CCK receptor proteins. As a result, the accuracy in studies relating, for example, to binding affinities and electrophysiology, was compromised by the inability to study a particular subtype without contamination by another type. Further, the inability to purify CCK receptor to sequenceable homogeneity prohibited cloning of receptor-encoding DNAs and the recombinant expression of a particular CCK receptor in a transformed cell line.

SUMMARY OF THE INVENTION

[0013] It is therefore an object of the present invention to provide a method for obtaining CCK receptor protein, in a homogeneous form suitable for amino acid sequencing.

[0014] It is also an object of the present invention to provide DNA molecules that encode CCK receptor protein, as well as host cells that are transformed with such a DNA and that expresses functional CCK receptor protein.

[0015] In accomplishing these and other objects, there has been provided, in accordance with one aspect of the present invention, an isolated DNA molecule encoding a CCK receptor protein. In a preferred embodiment, the DNA molecule comprises a first nucleotide sequence that consists of nucleotides 199 to 1485 of FIG. 1 (SEQ ID NO:13), or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 199 to 1485. In another preferred embodiment, a DNA molecule can comprise, in addition to the aforementioned first nucleotide sequence, a second nucleotide sequence consisting of nucleotides 154 to 198 of FIG. 1 (SEQ ID NO:13), which second nucleotide sequence is positioned immediately upstream of nucleotide 199 of the first nucleotide sequence.

[0016] In another preferred embodiment, an isolated DNA molecule encoding a CCK receptor protein comprises a nucleotide sequence consisting of nucleotides 136 to 1491 of FIG. 2 (SEQ ID NO:15) or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 136 to 1491 of FIG. 2 (SEQ ID NO:15).

[0017] In another preferred embodiment of the invention, an isolated DNA molecule encoding a human CCK receptor protein comprises a nucleotide sequence consisting of nucleotides 1 to 1341 of FIG. 12 (SEQ ID NO:28) or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 1 to 1341 of FIG. 12 (SEQ ID NO:28).

[0018] In another preferred embodiment of the invention, an isolated DNA molecule encoding a human CCK receptor protein comprises a nucleotide sequence consisting of nucleotides 154 to 1437 of FIG. 13, or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 154 to 1437 of FIG. 13.

[0019] In accordance with another aspect of the present invention, an isolated CCK receptor protein is provided that is sufficiently pure to be sequencable. The isolated CCK receptor protein can have the amino acid sequence shown, for example, in any of FIGS. 1, 2, 12 (SEQ ID NOS. 14, 16 and 29, respectively) and 13. In another preferred embodiment, an isolated CCK receptor protein having an amino acid sequence corresponding to that of amino acids 16-444 of FIG. 1 is provided.

[0020] In accordance with another aspect of the present invention, a cell is provided that is transformed with a DNA molecule encoding a CCK receptor protein, where the cell expresses a heterologous polypeptide that possesses a biological activity characteristic of CCK receptor protein.

[0021] In accordance with yet another aspect of the present invention, a method is provided for purifying a cholecystokinin receptor, comprising the steps of

[0022] (a) solubilizing a biological preparation containing cholecystokinin receptor in 1% digitonin,

[0023] (b) applying the solubilized receptor preparation to a cationic exchange resin and purifying the eluate of the resin,

[0024] (c) applying the purified eluate to an agarose-bound lectin, and

[0025] (d) applying an eluate of step (c) to a cibacron blue sepharose column.

BRIEF DESCRIPTION OF THE DRAWINGS

[0026]FIG. 1. Nucleotide and deduced amino acid sequences (SEQ ID NOS. 13 and 14) of the rat pancreatic CCK_(A) receptor cDNA clone. The solid lines labelled with Roman numerals delineate the putative seven transmembrane domains predicted by Kyte Doolittle criteria, see J. Mol. Biol. 157: 105-32 (1982), and homology with other G-protein receptor superfamily members. Amino acid sequence enclosed within brackets and labelled with Arabic numerals correspond to the five internal peptide sequences obtained following CNBr cleavage or Lys-C digestion of the purified CCK_(A) receptor protein. The triangles indicate four potential sites of N-linked glycosylation.

[0027]FIG. 2. Nucleotide and deduced amino acid sequences (SEQ ID NOS. 15 and 16) of the rat brain CCK_(B) receptor cDNA clone. The solid lines labelled with Roman numerals I-VII delineate the putative transmembrane domains predicted by Kyte-Doolittle criteria and homology with CCK_(A) type receptor, as well as other G-protein-coupled receptor superfamily members. The solid triangles indicate four potential sites for N-linked glycosylation. The solid bars indicate the three potential sites for serine phosphorylation and the solid circles indicate cysteine residues, which are potential sites for either disulfide bridge formation (residues #127 and #205) or palmitoylation (residue #413).

[0028]FIG. 3. Alignment of the rat CCK_(B) receptor (RCCKBR, SEQ ID NO:16, rat CCK_(A) receptor (RCCKAR, SEQ ID NO:14), mouse gastrin-releasing peptide receptor (MGRPR, SEQ ID NO:17), rat substance K receptor (RSKR, SEQ ID NO:19), rat substance P receptor (RSPR, SEQ ID NO:20) and rat neuromedin B receptor (RNMBR, SEQ ID NO:18) protein sequences. The sequence of rat neuromedin K receptor (RNMKR, SEQ ID NO:21) is also shown in this Figure. Using the Pileup program sequence analysis package of the Genetics Computer Group, see Devereux et al., Nucleic Acids Research 12: 387 (1984), the CCK_(B) receptor deduced amino acid sequence (SEQ ID NO:16) was aligned for maximal homology to the deducted protein sequences of the CCK_(A) receptor (SEQ ID NO:14) and the five sequences (mouse gastrin-releasing peptide, rat neuromedin B, rat neuromedin K, rat substance K and rat substance P receptors, SEQ ID NOS. 17, 18, 21, 19 and 20, respectively) found to be the most homologous upon searching the Swissprot. release #20 and Pir. release #30 protein data banks. Shown here using single letter abbreviations for amino acids is the result of this alignment with shaded areas denoting conserved amino acids. The number of residues in the variable C terminus not displayed are in parenthesis. Solid lines labelled with Roman numerals indicate the seven putative transmembrane domains.

[0029]FIG. 4. Ability of CCK receptor agonists and antagonists to inhibit binding of ¹²⁵I-BH-CCK-8 to COS-7 cells expressing either CCK_(A) or CCK_(B) receptors. COS-7 cells were transfected with the expression vector PCDL-SRα containing either the CCK_(A) (top panel) or the CCK_(B) (bottom panel) receptor cDNA sequences. ¹²⁵I-BH-CCK8 (50 pM) was incubated either alone or with increasing concentrations of agonists (CCK-8 and gastrin-17-1) (left panel) or antagonists (L-364,718 and L-365,260) (right panel). Data is presented as percent saturable binding (total binding in the presence of radiolabelled hormone alone minus binding in the presence of 1 μM CCK-8). Each experiment was performed in duplicate and the results given are the means from at least two separate experiments.

[0030]FIG. 5. Expression of the CCK_(A) receptor in Xenopus oocytes. Ligand induced chloride currents measured in the same oocytes one (A) and two (B) days after injection of mRNA (25 ng) in vitro transcribed from CCK_(A) receptor cDNA cloned from rat pancreas. A. Response to agonists. Application of 1 μM CCK-8 (vertical arrows) elicits a response which desensitizes with repeated applications in the same oocyte. Application of 1 μM gastrin-releasing peptide and 4 μM substance P (diagonal arrows), interspersed between response evoking applications of CCK-8, fail to elicit responses. B. Inhibition by the specific CCK_(A) receptor antagonist, L-364,718. Application of 1 μM CCK-8 (vertical arrows) to the same oocyte shown in (A) two days after mRNA injection elicits a response which is completely inhibited by the coapplication of 5 μM L-364,718 (diagonal arrow). The response to 1 μM CCK-8 could not be restored following antagonist application despite prolonged washes with buffer. Experiments were repeated several times (n=12 for (A) and n=10 for (B)) in different oocytes, with similar results.

[0031]FIG. 6. Nucleotide and deduced amino acid sequence (SEQ ID NOS. 22 and 23) of the CCK_(A) receptor in guinea pig gallbladder and pancreas. The solid lines labelled with Roman numerals delineate the putative seven transmembrane domains predicted by Kyte-Doolittle criteria and homology with the other G-protein coupled receptor superfamily members. The solid triangles indicate the potential sites for N-linked glycosylation. The solid lines indicate potential sites for serine and threonine phosphorylation.

[0032]FIG. 7. Alignment of the guinea pig CCK_(A) receptor (GPCCKAR) and rat CCK_(A) receptor (RTCCKAR) deduced protein sequences (SEQ ID NOS. 24 and 14, respectively). Using the Gap program sequence analysis package of the Genetics Research Group the guinea pig CCK_(A) receptor deduced protein sequence was aligned for maximal homology with the rat CCK_(A) receptor deduced protein sequence. Solid lines denote amino acid identity, and dotted lines denote conservative substitutions. Solid lines labeled with Roman numerals indicate the seven putative transmembrane domains.

[0033]FIG. 8. Ability of CCK receptor agonists and antagonists to inhibit ¹²⁵I-BH-CCK-8 to COS-7 cells expressing guinea pig CCK_(A) receptor. COS-7 cells were transfected with the expression vector pCDL-SRα containing the CCK_(A) receptor cDNA sequence. ¹²⁵I-BH-CCK 8 (50 pM) was incubated either alone or with increasing concentrations of agonists (CCK-8 and Gastrin-17-1) (left panel) or antagonists (L-364,718 and L-365,260) (right panel). Data are presented as percent saturable binding (total binding in the presence of radiolabelled hormone alone minus binding in the presence of 1 μM CCK-8). The results given are means of values from at least three experiments performed in duplicate. Vertical bars are standard deviations from the mean.

[0034]FIG. 9. Nucleotide and deduced amino acid sequence (SEQ ID NOS. 25 and 26) of the CCK_(B) receptor in guinea pig gallbladder and pancreas. The solid lines labeled with Roman numerals delineate the putative seven transmembrane domains predicted by Kyte-Doolittle criteria and homology with other G-protein coupled receptor superfamily members. The solid triangles indicate the potential sites for N-linked glycoyslation. The solid lines indicate potential sites for serine and threonine phosphorylation.

[0035]FIG. 10. Alignment of the guinea pig CCK_(B) receptor (GPCCKBR SEQ ID NO:26) with the rat CCK_(B) receptor (RTCCKBR SEQ ID NO:16) and the canine gastrin receptor (CANGASR SEQ ID NO:27) deduced protein sequences. Using the Pileup program sequence analysis package of the Genetics Research Group, the guinea pig CCK_(B) receptor deduced protein sequence was aligned for maximal homology with the rat CCK_(B) receptor and canine gastrin receptor deduced protein sequences. Solid lines labeled with Roman numerals indicate the seven putative transmembrane domains. Boxed areas denote amino acids not identical between the guinea pig CCK_(B) receptor and the rat CCK_(B) and/or gastrin receptors.

[0036]FIG. 11. Ability of CCK receptor agonists and antagonists to inhibit ¹²⁵BH-CCK-8 to COS-7 cells expressing the guinea pig CCK_(B) receptor. COS-7 cells were transfected with the expression vector pCDL-SRα containing the CCK_(B) receptor cDNA sequence. ¹²⁵I-BH-CCK 8 (50 pM) was incubated either alone or with increasing concentrations of agonists (CCK-8 and Gastrin-17-1) (left panel or antagonists (L-364,718 and L-365,260) (right panel). Data are presented as percent saturable binding (total binding in the presence of radiolabelled hormone alone minus binding in the presence of 1 μM CCK-8). The results given are means of values from at least three experiments performed in duplicate. Vertical bars are standard deviations from the mean.

[0037]FIG. 12. The nucleotide and deduced amino acid sequences (SEQ ID NOS. 28 and 29) of the human CCK_(B) receptor cDNA for both brain and stomach.

[0038]FIG. 13. The nucleotide and deduced amino acid sequences of the human CCK_(A) receptor cDNA.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

[0039] An unconventional approach to purifying CCK receptor protein to sequenceable-grade homogeneity has been discovered. By means of this approach, CCK receptor protein now can be obtained and sequenced routinely from a variety of sources. From the sequence information thus obtained it is possible, pursuant to the present invention, to prepare oligonucleotides suitable for cloning CCK receptor genes.

[0040] In this context, “CCK receptor” denotes any from a group of proteins that displays a characteristic CCK binding affinity and that is encoded by a nucleotide sequence which hybridizes an oligonucleotide probe designed in accordance with the criteria elaborated herein.

[0041] Examples of CCK receptors proteins obtained and sequenced according to the invention include, but are not limited to, CCK_(A) and CCK_(B)/gastrin receptors. By means of the present invention, it has been discovered that the CCK_(B) and gastrin receptors are the same protein and possess identical nucleotide sequences in both dog and rat species. Accordingly, the CCK_(B)/gastrin receptor is designated simply as CCK_(B) receptor, hereinafter.

[0042] With regard to probe design, for example, polymerase chain reaction (PCR) primers can be made utilizing polynucleotide regions common to both the CCK_(A) gene and the CCK_(B) gene, such as a portion of the coding sequence which encodes one or more of the seven transmembrane domains (see FIGS. 1 and 2). PCR primers designed along these lines can be degenerate in order to hybridize to members of the CCK receptor family that are not identical to CCK_(A) or CCK_(B) receptor.

[0043] A DNA molecule that is a coding sequence for a CCK receptor protein is defined according to the present invention. In preferred embodiments, the DNA molecule comprises a nucleotide sequence consisting of nucleotides 199 to 1485 of FIG. 1 (SEQ ID NO:13), or of nucleotides 154 to 1485 of FIG. 1 (SEQ ID NO: 13), or of a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 199 to 1485. In another preferred embodiment, the molecule comprises nucleotides 136 to 1491 of FIG. 2 (SEQ ID NO:15) or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 136 to 1491. In yet another preferred embodiment, the molecule comprises nucleotides 1 to 1341 of FIG. 12 (SEQ ID NO:28) or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting of nucleotides 1 to 1341.

[0044] The targeted gene is amplified using standard PCR technology, and the product obtained by amplification then is used to probe, under high stringency conditions, a genomic or cDNA library containing a polynucleotide coding for CCK receptor. High stringency conditions are illustrated by 0.1×SSC (0.015 saline sodium citrate, 0.15 M NaCl) at a temperature of 55° C. PCR RACE and Anchored methodologies as described, for example, by Frohman et al., Proc. Nat'l Acad. Sci USA 85: 8998-9002 (1988), are suitable for use in this context.

[0045] Alternatively, an oligonucleotide probe can be designed for use in screening genomic or cDNA libraries that contain polynucleotides coding for CCK receptor. Thus, one would screen for hybridization using a labeled probe which is a full-length or a partial-length CCK_(A) or CCK_(B) receptor coding sequence. An exemplary screening process entails screening first under low stringency conditions, then under high stringency, and selecting those plaques which do not hybridize under the latter conditions. Conditions for low stringency include, for example, 2×SSC at a temperature from 37°-42° C. Once a probe is obtained and a library screened, conventional genetic engineering methodologies may be employed to clone and express the receptor gene in a cell line.

[0046] The term “CCK binding affinity” is used in this description, with reference to those molecules that have a high affinity for CCK-8, desulfated CCK-8, CCK-33, CCK-4, desulfated or sulfated gastrin 17-1, gastrin 17-2, pentagastrin or other CCK analogues or CCK family members which are non-sulfated or sulfated. A “high affinity” molecule, in this context is one having a binding affinity constant, K_(d), for CCK or CCK analogues that is within the range of 10 nanomolar or smaller (picomolar).

[0047] Essentially similar approaches can be used, pursuant to the present invention, to identify and clone other CCK receptor genes or CCK_(A) and CCK_(B) receptor proteins from different mammalian species, such as human, mouse, rabbit, dog, cat, ferret, goat, pig and monkey. That is, other CCK receptors can be obtained by PCR cloning or library-hybridization screening, or by purification from natural sources. CCK receptor purified to homogeneity from a natural source also can be sequenced. The sequence information in turn is applied to design a probe, as described above, for use in a cloning or hybridization-screening regimen.

[0048] Cells which can be transformed with a vector containing receptor DNA of the present invention include eukaryotic cells which can accommodate post-translational processing, such as glycosylation and palmitoylation, and which preferably do not express CCK receptor protein naturally. Illustrative of such eukaryotic cells are Xenopus oocytes, COS-7 and other COS cells, CHO and Swiss 3T3 cells. It is particularly preferred that the host cell possess a “second messenger” pathway, such as a G protein/protein kinase C pathway as found in pancreatic acinar cells, which is relevant to the activity of the CCK receptor in the native cell.

[0049] Transformed eukaryotic cell lines are useful for studying the receptor in an environment similar to its native environment, for example, in the context of studying the electrophysiology or binding properties of the receptor. Additionally, a prokaryotic or an insect host cell can be used for expressing CCK receptor, thereby to produce large amounts of receptor for immunological purposes or for studying protein structure, for example, crystallographically.

[0050] To confirm that a clone encodes a particular CCK receptor, ligand dose inhibition studies can be performed in cells transfected with the specific receptor cDNA insert. Examples of inhibition studies along these lines are described by Knapp et al., J. Pharm. Exp. Ther. 265: 3 (1990), by Grider et al. Gastrointest. Liver Physiol. 22: 184-90 (1990), and by Roche et al., Gastrointest. Liver Physiol. 23: 182-88 (1991), the respective contents of which are hereby incorporated by reference.

[0051] As mentioned previously, the present invention relates to obtaining CCK receptor protein in a form that is sufficiently homogeneous to permit sequencing of the receptor. CCK receptor protein is obtained from smooth muscle cells of the gastrointestinal tract, such as stomach or gall bladder. Other gastrointestinal cells which express CCK receptor include gastric mucosal isolates, containing a mixture of parietal, chief, ECL and D cells. Cells of the central or peripheral nervous system are another source of CCK receptors. In addition to natural tissue, CCK receptor protein can be obtained from cultured cell lines, such as AR42-J, CHP212 and NCI-H209, or from COS-7 cells transfected with either the CCK_(A) or the CCK_(B) receptor encoding-DNA (see Example 3).

[0052] CCK receptors isolated from such sources can be purified by a regimen which includes the steps of (a) solubilizing a biological preparation containing cholecystokinin receptor in 1% digitonin, (b) applying said solubilized receptor preparation to a cationic exchange resin, and purifying the eluate of said resin (c) applying said purified eluate to a agarose-bound lectin column, preferably a wheat-germ agglutinin agarose column, (d) applying eluate of step (c) to a cibacron blue sepharose column, (e) trace-labeling and subjecting purified receptor to SDS-PAGE gel electrophoresis (reducing conditions) to obtain purified receptor electroeluted from the gel. In connection with this purification process, other affinity columns having similar properties, for example, Ulex europaeus agglutinin-I-agarose, can be used.

[0053] The amino acid sequence of an isolated CCK receptor purified by the above method can be determined, hence the term “isolated CCK receptor protein”, in this context, refers to a CCK receptor protein of sufficient purity to be sequencable via the modified Edman degradation methodology (mixture sequencing and OPA blocking) as described in Example 1. A nucleotide probe can be synthesized which corresponds to the amino acid sequence of the isolated CCK protein or fragments thereof. This nucleotide probe can be used to isolate other CCK proteins in the manner described above.

[0054] Isolated CCK receptor proteins or fragments thereof are useful for obtaining antibodies which can recognize CCK-expressing cells. Although the length of a CCK receptor polypeptide or fragment thereof used to stimulate antibody production is not critical, the requirement for immunogenicity may require that the polypeptide be attached to a immunogenicity-imparting carrier, e.g., a particulate carrier like a liposome or a soluble macromolecule (protein or polysaccharide) with a molecular weight in the range of about 10,000 to 1,000,000, or be administered with an adjuvant, such as complete Freund's adjuvant. For artificial polypeptides, as distinguished from CCK fragments, maximum length is determined largely by the limits of techniques readily available for peptide synthesis, that being about fifty amino acids. Thus, a synthetic polypeptide of the present invention is preferably between four and about fifty amino acids in length.

[0055] In this context, the term “antibody” encompasses monoclonal and polyclonal antibodies. Such an antibody can belong to any antibody class (IgG, IgM, IgA, etc.). For monoclonal antibody (Mab) production, one generally proceeds by isolating lymphocytes of an animal which has been sensitized with CCK_(A) or the CCK_(B) receptor polypeptide, and fusing them with myeloma cells, producing hybridomas. The cloned hybridomas are then screened for production of antibodies that bind preferentially to either the CCK_(A) or the CCK_(B) receptor.

[0056] “Antibody” also encompasses fragments, like Fab and F(ab′)₂, of anti-CCK_(A) or anti-CCK_(B) antibodies, and conjugates of such fragments, and so-called “antigen binding proteins” (single-chain antibodies) which are based on anti-CCK_(A) or anti-CCK_(B) antibodies, in accordance, for example, with U.S. Pat. No. 4,704,692, the contents of which are hereby incorporated by reference. Alternatively, Mabs or a fragment thereof within the present invention can be produced using conventional procedures via the expression of isolated DNA which codes for variable regions of such an Mab in host cells like E. coli, see, e.g., Ward, et al., Nature, 341:544-546 (1989), or transfected murine myeloma cells. See Gillies, et al., Biotechnol. 7: 799-804 (1989); Nakatani, et al., Biotechnol. 7: 805-10 (1989).

[0057] Diagnostic applications of these antibodies are exemplified, according to the present invention, by the use of a kit containing an anti-CCK_(A) or an anti-CCK_(B) antibody, which undergoes a reaction with a biological sample to determine the extent of CCK_(A) or CCK_(B) protein expression. Such a reaction involves the binding of anti-CCK_(A) antibody to CCK_(A) antigen or the binding of anti-CCK_(B) antibody to CCK_(B) antigen. The observation of an antibody-antigen complex in a biological sample would indicate a positive result. A kit of this sort could be used to detect the extent of expression of CCK receptor in a particular biological sample from an individual, animal, or cell line.

[0058] Pursuant to another aspect of the present invention, a CCK receptor-antagonist or agonist can be site-directed to CCK-expressing cells. This is accomplished by conjugating such a compound to a monoclonal antibody, such as an anti-CCK_(A) or anti-CCK_(B) antibody. In a preferred embodiment, a CCK inhibitory compound, such as the specific CCK_(A) receptor-antagonist, L-364,718 or the specific CCK_(B) receptor-antagonist, L-365,260, is conjugated to an antibody. Conjugation is accomplished by conventional methods for antibody-toxin linkage, such as described by Hertler et al., J. Clin. Oncol. 7(12): 1932 (1989), which is incorporated by reference herein. The antibody conjugates described according to the invention can be used to target CCK-expressing cells, which are present in colon, gastric, and pancreatic tumors, as well as in small cell lung carcinomas.

[0059] The present invention is further described with reference to the following, illustrative examples.

EXAMPLE 1

[0060] Isolation and Cloning of CCK_(A) Receptor

[0061] Purification of CCK_(A) Receptors From Rat Pancreas

[0062] Rat pancreatic membranes were prepared from 250 male Sprague-Dawley rat pancreases and solubilized in 2.5 liters of buffer (10 mM HEPES (pH 6.5), 1 mM EGTA, 5 mM MgCl₂, 1 μM dithiothreitol (DTT), 1 μM leupeptin, 1 μM pepstatin, 0.5 mM phenylmethylsulfonyl fluoride (PMSF), 140 μg/ml bacitracin, 200 μg/ml benzamidine and soybean trypsin inhibitor 0.1 mg/ml at 4° C.) with 1% (weight/volume) digitonin using similar methods, as described by Szecowka et al., Reg. Pep. 10: 71 (1985), and Chang et al., Biochem J. 3: 1709 (1987). Soluble extract was applied to a S-Sepharose (Pharmacia) cationic exchange column (4×15 cm), washed with 600 ml of buffer containing 100 mM NaCl and 0.2% digitonin and eluted with buffer containing 300 mM NaCl and 0.2% digitonin. Receptor purification was followed by a radiolabelled antagonist ([³H]L-364,718) binding assay until final purification by SDS-PAGE. Elution fractions containing [³H]L-364,718 binding activity were pooled, diluted with ⅓ volume of buffer and applied to a wheat-germ agglutinin agarose (Vector Labs) affinity column (1.7 ml packed volume in a Bio-Rad Econo Column), washed overnight with 100 column volumes of buffer containing 150 mM NaCl and 0.1% digitonin and eluted stepwise with 3×1.4 ml volumes of wash buffer plus 16 mM N,N′,N″-triacetylchitotriose. The pooled elutions were then applied to a Cibacron Blue Sepharose (Pharmacia) column (0.5 ml packed volume in a Bio-Rad Econo Column), washed and eluted with five 0.5 ml volumes of buffer with 1 mM Cibacron F3GA in a method similar to the above wheat-germ affinity chromatography. Purified receptor was then trace labelled with ¹²⁵I by the chloramine T method and subjected to preparative SDS-PAGE (11%) under reducing conditions (50 mM DTT). The major Coomassie brilliant blue stained band corresponding to >90% of the radioactivity was cut, electroeluted, ethanol precipitated and submitted for amino acid analysis and sequencing. Each step of the receptor purification was assayed for protein either by the method of Bradford, Anal. Biochem. 72: 248 (1976), and corrected for the presence of digitonin, or on the basis of amino acid compositional analysis (Beckman analyzer).

[0063] Automated Protein Sequence Analysis

[0064] Ten micrograms of intact purified rat pancreatic CCK_(A) receptor was subjected to automated sequence analysis on an Applied Biosystems model 475A gas phase sequencer.

[0065] Chemical and Enzymatic Cleavage of the CCK Receptor

[0066] Cyanogen bromide (CNBr) cleavage of the CCK receptor was performed on the sequencer filter after five cycles of Edman degradation of the intact receptor using standard methods. The chemically cleaved receptor was then resequenced.

[0067] Lysyl Endopeptidase (Wako Chemicals, Osaka, Japan) digestion was performed on 10 μg of the purified CCK_(A) receptor in 150 μl of 0.1 M Tris HCL, pH 9.0. Enzyme (1:20 relative to the receptor weight) was added at 0 and 2 hours and the reaction was continued for a total of 16 hours at 37° C. and then fractionated by HPLC.

[0068] Sequencing of the mixture of peptides was performed on chemical and enzymatic digests to determine the cycle at which proline appeared at the amino terminus. Primary amines of the mixture of peptides were blocked in subsequent sequencing runs where prolines appeared using o-phthalaldehyde (Pierce Chem. Co.) 0.2% (w/v) in n-butyl chloride containing 0.6% (w/v) β-mercaptoethanol delivered through the S1 reservoir instead of R1 (phenylisothiocyanate) at predetermined cycles.

[0069] HPLC Separation of CCK Receptor Peptides

[0070] CCK receptor products were fractionated on a 2.1 mm×3 cm C₄ reverse phase column (Aquapore Bu-300, Brownlee Labs).

[0071] Construction of a Rat Pancreatic cDNA Library and Isolation of cDNA Clones

[0072] Messenger RNA was isolated from male, Sprague-Dawley rat pancreas. Oligo dT-primed cDNA of greater than 2 Kb in size was size selected by electrophoresis on an agarose gel. A library was constructed in lambda Zap II (Stratagene) and in vitro packaged according to established methods. Approximately 7.5×10⁵ plaques were screened with a ³²P labelled, randomly primed probe using a 527 basepair product of the MOPAC PCR described below. Samples on duplicate filters were hybridized at 42° C. overnight, washed once at room temperature for 5 minutes in 300 nM NaCl, 3 mM NaCitrate (2×SSC), 0.1% sodium dodecyl sulfate (SDS) and twice at 45° C. for 20 minutes in 0.1×SSC, and 0.1% SDS, dried and autoradiographed for one to two days. Positive clones were plaque purified and the phagemid pBluescript containing the insert was in vivo excised using the helper phage R408 according to standard protocol (Stratagene).

[0073] DNA Sequencing

[0074] Sequencing of both DNA strands was done by the dideoxy chain-termination method of Sanger with Sequenase version 2 (United States Biochemical).

[0075] cDNA Cloning Using the Polymerase Chain Reaction (PCR)

[0076] Mixed oligonucleotides primed amplification of cDNA (MOPAC) was performed using two groups of degenerate primers based on the amino acid sequence from peptides 1 and 3 (FIG. 1 SEQ ID NO:13). The sense group of primers, based on peptide 1, was 72 fold degenerate, included two inosines and had the following sequence (SEQ ID NO:1): 5′-ATGCCIAT/(CG)AAC/TCTIATC/(AT)CCA/(GCT)AA-3′. The antisense group of primers, based on peptide 3, was 80 fold degenerate and consisted of two groups of 32 and 48 fold degenerate primers with the following sequences respectively: (SEQ ID NO:2) 5′CCA/GTCA/GCTA/GTCT/CTCA/GTA-3′ and (SEQ ID NO:3) 5′-CCA/GTCA/(TG)GAA/GTCT/CTCA/GTA-3′. One hundred picomoles of each group of primers were used in the PCR reaction. Four percent of the cDNA reversed transcribed from 1 μg of rat pancreatic mRNA was used as a template. The conditions for the PCR were as follows: denaturation for 1 minute at 94° C., annealing for 1.5 minutes at 50° C. and extension for 1 minute at 72° C. The reaction was carried out for 36 cycles. Two percent of the PCR product served as a template for asymmetric PCR using either the sense or antisense group of primers under otherwise same reaction conditions for an additional 25 cycles. The product of the asymmetric PCR was sequenced to confirm its specificity and to provide sequence needed to generate nondegenerate primers for subsequent PCR.

[0077] The remaining 3′ coding and untranslated sequence was obtained using the methods of rapid amplification of cDNA ends (RACE) and anchored PCR. RACE PCR was performed using 25 pmoles of the gene specific primers, (SEQ ID NO: 4) 5′-GCCAGCCAGAAGAAATCTGCC-3′ for the first round and the nested primer (SEQ ID NO:5) 5 ′-AGCCGAGCACTGGCAGCAGCA-3′ for the second round. The RACE PCR conditions were as follows. First round: denaturation for 7 minutes at 95° C., annealing for 2 minutes at 58° C. and extension for 40 minutes at 7220 C. for first cycle; denaturation for 45 seconds at 94° C., annealing for 25 seconds at 58° C., and extension for 3 minutes at 72° C. for 19 cycles and a final similar cycle except extension was for 15 minutes. Second round RACE utilized 2% of the first round product, the nested primer above and the same conditions as the first round except for the omission of the first cycle and a total of 25 cycles. Anchored PCR utilized the unamplified cDNA library constructed in lambda Zap II described above as template DNA, the gene specific primer containing an Xba 1 site and 9 bp cap on the 5′ end, (SEQ ID NO:6) 5′-ACTGACTAGTCTAGATCAGCTG CCAACCTGATAGCC-3′ and the anchored primer from the vector also with an Xba 1 site and 9 pb cap, (SEQ ID NO:7) 5′ACTGACTAGTCTAGATAATACGACTCACTATAGGGCG-3′. PCR conditions were as follows: denaturation for 3 minutes at 94° C., annealing for 25 seconds at 61° C., extension for 2 minutes at 72° C. for the first cycle, followed by 33 similar cycles except for denaturation for 45 seconds and a final similar cycle except for extension for 15 minutes. The PCR product was digested with Xba 1, subcloned into pGEM (Promega) and sequenced using standard methods.

[0078] The CCK_(A) receptor open reading frame with 5′ and partial 3′ flanking sequence (nucleotides 5 to 1506, FIG. 1) was cloned using PCR. The sense primer (SEQ ID NO:8) 5′-ACTGACTAGTCTAGAAATGCTTGCCCAGATGCTCTG-3′ (excluding a 5′Xba 1 site and 9 bp cap) was obtained from sequence of a plaque purified clone resulting from cDNA library hybridization screening described above. The antisense primer (SEQ ID NO:9) 5′ACTGACTAGTCTAGACAGTGGACCAGGTGGAGTTCA-3′ (excluding the 5′Xba 1 site and 9 bp cap) was obtained from sequence of the product of anchored PCR described above. Single stranded cDNA reversed transcribed from rat pancreatic mRNA served as DNA template. The PCR conditions were the same as those used for anchored PCR described above. The PCR product was digested with Xba 1 and subcloned into the expression vector pcDNA-1 (Invitrogen) and sequenced.

[0079] Northern Blot Analysis of mRNAs

[0080] PolyA+ mRNA was isolated from tissue or cell culture lines, electrophoretically separated on a 1.4% agarose/formaldehyde gel, blotted onto Nytran (Schleicher and Schuell), hybridized with CCK_(A) receptor cDNA probe labelled with ³²P by random priming, washed and autoradiographed for 4 days.

[0081] In Vitro Transcription of the CCK Receptor and Expression in Xenopus oocytes

[0082] DNA was in vitro transcribed using T7 RNA polymerase from a CCK receptor clone template (5 to 1506, FIG. 1, SEQ NO:13) in pcDNA-1 (5 μg linearized with Apa 1) in the presence of the cap analog m⁷G(5′)ppp(5′)G as recommended by the manufacturer (Promega). Xenopus oocytes were injected with 50 nl of approximately 25 ng of transcribed RNA. At 1-2 days, oocytes were voltage clamped at −70 mv, ligands were applied rapidly and directly to the constantly perfused bath and the ligand dependent Cl⁻ current measured.

[0083] Pharmacological studies clearly demonstrate that the rat pancreas contains CCK receptors which are of the CCK_(A) subtype. (See, Jensen et al., Trends Pharmacol. Sci. 10: 418 (1989). Biochemical studies provide strong evidence on the basis of affinity crosslinking experiments with radiolabelled ligand that the receptors are highly glycosylated and have a molecular weight of 85-95 kDa. With this knowledge, 250 rat pancreases were used to purify the CCK_(A) receptor to homogeneity. A crude membrane preparation derived from the whole organ was solubilized in 1% digitonin and sequentially purified over three chromatographic columns, cationic exchange resin, wheat-germ agglutinin agarose and Blue sepharose. Starting with 11.7 gms of membrane protein this resulted in an approximately 14,600 fold increase in specific radiolabelled antagonist, [³H]L-364,718, binding activity in 260 μg of purified receptor protein. Radiolabelling of the purified receptor was ¹²⁵I by the chloramine T method followed by SDS-PAGE under denaturing conditions resulted in a single, broad band (suggesting heavy glycosylation) with molecular weight of 85-95 kDA. Purification on preparative SDS-PAGE and electroelution yielded 200 μg of homogeneous receptor for amino acid sequencing.

[0084] Initial attempts to obtain a sequence from 10 μg of purified intact CCK_(A) receptor were unsuccessful and indicated that the amino terminus of the receptor was blocked to Edman degradation. Treatment of the intact CCK_(A) receptor on the filter with CNBr after 5 sequencer cycles resulted in the generation of multiple signals upon resequencing which further suggested that the amino terminus was blocked. One of the signals generated on the first sequencing cycle after CNBr cleavage was a proline. Therefore, a second 10 μg of CCK_(A) receptor was handled similarly, except that a blocking step using O-phthaldehyde (OPA) was performed at the 1st cycle after CNBr cleavage. A single major signal was generated in the next cycle resulting in the sequence of peptide 1 (FIG. 1, SEQ ID NO:13). This same technique of mixture sequencing and OPA blocking of proline residues was also applied to a lysyl endoproteinase (Lys-C) digest of the intact CCK_(A) receptor where a proline was observed at cycle 2 of the mixture sequence. This resulted in the sequence of peptide 3 (FIG. 1, SEQ ID NO:13). Further sequence analysis was performed on peptides obtained from Lys-C digestion of intact CCK_(A) receptor followed by HPLC separation on a C₄ column. This resulted in peptides 2, 4 and 5 (FIG. 1, SEQ ID NO:13).

[0085] Based on the sequences of peptides 1 and 3 (FIG. 1, SEQ ID NO:13), two groups of mixed degenerate oligonucleotides were synthesized and MOPAC PCR was used on single stranded cDNA reversed transcribed from rat pancreatic mRNA. This resulted in a 527 bp product (corresponding to sequence 481-1007, FIG. 1, SEQ ID NO:13) which, after ³²P random prime labelling, was used for hybridization screening of an oligo (dT) primed cDNA library constructed from rat pancreas in the vector Lambda Zap II. Twenty-six strongly hybridizing clones were identified on initial screening of approximately 7.5×10⁵ clones. However, after three rounds of plaque purification, only 6 clones remained. The six clones were in vivo excised with R408 helper phage into pBluescript and sequenced. All 6 of these clones contained various mutational deletions of the entire 3′ end of the hybridizing sequence. Repeat screening of the library using other bacterial species including phenotypically Rec A and B positive Sure cells (Stratagene) gave similar results. Therefore, only partial sequence corresponding to the 5′ untranslated and partial 5′ coding region (sequence 1-985, FIG. 1, SEQ ID NO:13) was obtained.

[0086] The remainder of the CCK_(A) receptor sequence was obtained using PCR cloning methods to circumvent the high rate of mutation during amplification in bacteria. With knowledge of the 5′ end of the CCK_(A) receptor cDNA sequence, gene specific primers were synthesized corresponding to sequences 928-948 and 959-979 (FIG. 1, SEQ ID NO: 13), and used in the first and second rounds, respectively, of the RACE protocol. This resulted in only an additional 366 bp of sequence (sequence 986-1351, FIG. 1, SEQ ID NO:13) because the PCR preferentially amplified truncated products. The remaining 3′ sequence was then obtained by the method of “anchored” PCR using a gene specific primer corresponding to sequence 1102-1122 (FIG. 1, SEQ ID NO: 13) and the Lambda Zap II, vector-specific T7 primer/promoter. An additional 155 bp of sequence completed the 3′ coding and part of the 3′ untranslated sequence to give a total of 1506 bp. The first in frame ATG consistent with a consensus translation initiation site represents the start codon of a single long open reading frame encoding a unique 444 amino acid protein with predicted molecular weight of 49.6 kDa. The five independent peptide sequences obtained from the CNBr cleavage and Lys-C digestion of the purified CCK_(A) receptor protein are present within the predicted protein sequence (FIG. 1, SEQ ID NO: 13) and confirm that the combined DNA sequence derived from cDNA cloning by library hybridization of PCR codes for the purified protein having high affinity for the specific antagonist, L-364,718. The sequence allows for four potential N-linked glycosylation sites, three in the amino terminus and one in the extracellular fourth loop (FIG. 1, SEQ ID NO:13) which is consistent with the heavily glycosylated 85-95 kDa band seen on Coomassie staining and subsequent four step reduction to a final molecular weight of approximately 42 kDa following deglycosylation with Endogylcosidase F (FIG. 1, SEQ ID NO:13). There are four potential sites for protein kinase C phosphorylation, 3 on serine in the large intracellular fifth loop (residues 260, 264 and 275) and one on threonine in the cytoplasmic tail (residue 424) which is consistent with previous data indicating predominately serine, minor threonine and no tyrosine phosphorylation of the CCK_(A) receptor in rat pancreas following CCK and phorbol 12-myristate 13-acetate stimulation and inhibition of phosphorylation by staurosporine.

[0087] A hydropathy plot of the predicted amino acid sequence, using the criteria of Kyte and Doolittle and homology to other G-protein receptor superfamily members, identifies seven regions of hydrophobic residues corresponding to putative transmembrane domains expected for members of the G protein-coupled superfamily of receptors. This is consistent with evidence that G proteins couple CCK_(A) receptors to phospholipase C in exocrine pancreas. A comparison of the CCK_(A) receptor deduced protein sequence with all protein sequences in available databanks found that the five most homologous proteins (rat neuromedin K, bovine substance K, mouse gastrin-releasing peptide, rat substance P and rat beta-1 adrenergic receptors) having 27-30% amino acid identity and 50-54% similarity were all members of the G-protein receptor superfamily.

[0088] High stringency northern blot analysis of organ- and tissue-specific polyadenylated RNA using a full coding region probe revealed a 2.7 kb hybridizing transcript in rat pancreas and a rat pancreatic acinar carcinoma cell line, AR42J. No hybridization was observed in rat brain or guinea pig gallbladder, organs known to posses CCK receptors, presumably because of low level expression and/or low amount of expressing cell representation in these organs or different receptor subtypes unable to hybridize under the stringent conditions employed. As expected, no signal was observed in liver, muscle or kidney. The size of the hybridizing transcript in consistent with the cloned cDNA size, and the 3 kb size estimated from sucrose gradient fractionation of AR42J mRNA functionally expressed in Xenopus oocytes.

[0089] To further demonstrate that the protein sequence encoded by the cDNA represents a functional CCK_(A) receptor, a capped in vitro transcript of a cDNA clone containing the entire coding region and 5′ untranslated sequence (5 to 1506 bp FIG. 1, SEQ ID NO:13) was injected into Xenopus oocytes and assayed for specific, cell surface, functional expression 1 and 2 days later (FIG. 5). The oocytes responded to CCK octapeptide (CCK-8) (FIG. 5A) but not to gastrin-releasing peptide (GRP), substance P (SP) nor acetylcholine (ACh). Repeated challenges with CCK-8 caused only a moderate desensitization of the response (FIG. 5A) and allowed an internal positive control for the effect of the specific CCK_(A) receptor antagonist, L-364,718. Application of the specific, CCK_(A) receptor antagonist, L-364,718, after an initial response to CCK-8 inhibited any further response to repeated applications of CCK-8 (FIG. 5B). Inhibition was specific for CCK_(A) receptors (i.e., there was no inhibition of SP or ACh response in oocytes injected with their respective receptor mRNAs). Oocytes injected with rat pancreatic total mRNA showed a typical CCK-8 evoked response. Coinjection of the same mRNA with an antisense oligo (reverse complement of nucleotides 265 to 295) completely abolished the response to CCK-8.

EXAMPLE 2

[0090] Cloning of CCK_(B) Receptor

[0091] cDNA Construction and Isolation of cDNA Clones

[0092] Total RNA was isolated from the rat pancreatic carcinoma cultured cell line, AR42-J and rat brain cortex using a low temperature GITC/GnHCI extraction procedure as described by Han et al., Biochem. 26: 1617 (1987), and poly (A)+ RNA was isolated using oligo dT cellulose. Separate cDNA libraries were constructed from each source of poly (A)+ RNA. Oligo dT primed cDNA greater than 2 kilobases was size-selected by agarose gel electrophoresis, electroeluted, adapted with Eco RI, ligated into lambda gt10 arms, and in vitro packaged according to methods described by Davis et al., BASIC METHODS IN MOLECULAR BIOLOGY (1988). Each library (7.5×10⁵ plaques) was screened with a ³²P labelled, randomly primed probe corresponding to the coding region of the CCK_(A) receptor cDNA isolated from rat pancreas initially under conditions of low and later high stringency (three 20-min washes at 42° C. with 2×SSC/0.1% SDS for low stringency screening and three 20-min washes at 55° C. with 0.1×SSC/0.1% SDS for high stringency washes (1×SSC=150 mM NaCl/15 mM sodium citrate, pH 7.0)). Several clones that hybridized at low stringency were plaque-purified from the AR42-J cell library and subcloned into pCDL-SRα at the xba I site. A ³²P-labelled, randomly primed probe corresponding to the open reading frame of the AR42-J cDNA clones was used to screen another 7.5×10⁵ plaques from the rat brain cortex library under conditions of high stringency. Several purified and subcloned into the vector pCDL-SRα at the Xba I site.

[0093] DNA Sequencing

[0094] Both strands of two cDNA clones isolated from the AR42-J cell library were sequenced by the dideoxy chain termination method of Sanger using Sequenase 2.0 (U.S. Biochemical). One of the cDNA clones isolated from the rat brain cortex library and the product of PCR cloning from the rat brain subcortex cDNA were cycle sequenced (Bethesda Research Labs).

[0095] DNA and Protein Sequence Analysis

[0096] Nucleotide and amino acid sequences were analyzed with the Wisconsin Genetics Computer Group software package, by means of the Gap program, as described by Devereux et al., Nucleic Acids Res. 12:387 (1984).

[0097] Northern Blot Analysis of mRNAs

[0098] Poly (A)+ RNA was isolated using a low temperature GITC/GnHCI extraction, according to the method of Han et al., supra, from rat pancreas, brain cortex and subcortex, striated muscle, liver, kidney, the rat pancreatic acinar carcinoma cell line AR42-J, and guinea pig gallbladder. (Rats do not have gallbladders.) Four micrograms of poly (A)+ RNA per lane were electrophoretically separated on a 1.4% agarose/formaldehyde gel and blotted onto Nytran (Schleicher and Schuell, Keene, N.H.). The blot was hybridized separately with CCK_(A) AND CCK_(B) full length coding region probes, which had been ³²P-labelled (random-primed). The blot was washed under conditions of high stringency (three 20-minute washes at 55% C with 0.1×SSC/0.1% SDS) and exposed for 24 hours in a phosphorimager (Molecular Dynamics) to prepare an autoradiograph.

[0099] To obtain the rat brain cCKB receptor cDNA, the ³²P labelled, randomly primed full length coding region of the CCK_(A) receptor isolated from rat pancreas was used. Approximately 7.5×10⁵ plaques from two rat brain cDNA libraries constructed from cortex and subcortex were screened under conditions of low and high stringency to isolate clones corresponding to pharmacologically described CCK_(B) receptors, as described by Saito et al., Science 1155 (1980). When this approach did not yield any hybridizing plaques, a cDNA library was constructed from AR42-J cells, a rat pancreatic acinar carcinoma cell line known to express predominantly (80%) CCK_(B) type CCK receptors. Several candidate clones were isolated only under low stringency conditions, two of which contained a long open reading frame highly homologous to the CCK_(A) receptor cDNA.

[0100] To confirm that the CCK_(B) receptor isolated from the AR42-J cells was the same CCK_(B) receptor pharmacologically identified in rat brain (Lambert et al., Reg. Pept. 322: 151 (1991), 7.5×10⁵ plaques were screened from the cortex cDNA library using the new CCK_(B) open reading frame sequence as a ³²P labelled, randomly-primed probe. Only high stringency hybridizing clones were isolated, one of which was a 2,243 bp clone containing identical cDNA sequence to the two clones isolated from the AR42-J cell cDNA library (FIG. 1, SEQ ID NO:13).

[0101] A comparison of the nucleotide sequence of the CCK_(B) receptor cDNA to the CCK_(A) receptor cDNA sequence (SEQ ID NOS. 15 and 13, respectively) reveals a 54% homology, higher than any other sequence reported to date. The first in frame ATG consistent with a consensus translation initiation site initiates a single long open reading frame encoding a unique 452 amino acid protein with predicted molecular weight of 48,954 Da. Similar to the CCK_(A) receptor, the sequence contains four potential N-linked glycosylation sites, three in the amino terminus and one in the fourth extracellular loop, which would account for the larger than predicted molecular weight of 90 kDa reported in affinity crosslinking studies. There is one potential site for protein kinase C phosphorylation on serine in the first intracellular loop (serine residue #82) and two potential sites for protein kinase A phosphorylation on serine-154 in the second intracellular loop and serine-442 in the cytoplasmic tail and none in the third intracellular loop, unlike the CCK_(A) receptor.

[0102] The predicted amino acid sequences of the CCK_(A) and CCK_(B) receptors (SEQ ID NOS. 14 and 16, respectively) have a 48% identity which is in the expected range for receptors within the same family and is higher than any other reported protein. A hydropathy plot of the predicted amino acid sequence using criteria of Kyte and Doolittle and homology to the other G-protein receptor superfamily members identifies seven regions of hydrophobic residues corresponding to putative transmembrane domains. Cysteine residues in the first and second extracellular domains are conserved in both receptors as well as other G protein-coupled receptors and may form a disulfide bridge. A cysteine residue in the C-terminal region (residue #377) conserved in most of the G protein coupled receptors may be a membrane anchoring palmitoylation site. An aspartate commonly found in the third transmembrane domain of charged amine ligand binding receptors is absent as expected for these peptide hormone receptors.

[0103] Several other areas of CCK_(A) and CCK_(B) amino acid sequence homology also are commonly conserved among other G protein-coupled receptors, indicating their common membership in the G protein-coupled receptor superfamily. The five most similar proteins were mouse gastrin-releasing peptide receptor, rat neuromedin B receptor, rat substance K receptor, rat substance P receptor, and rat neuromedin K receptor, which further supports their suspected membership in the G-protein coupled receptor superfamily (FIG. 3, SEQ ID NOS. 16, 14, 17, 19, 20, 18 and 21). The homology between the two CCK receptor amino acid sequences diverge most notably in the length and composition of their third intracellular loops. This difference may contribute to a difference in G protein coupling specificity since this region has been shown to be important in G protein coupling specificity of other receptors. Cysteines in the first and second extracellular domains are conserved in both receptors and may form a disulfide bridge required for stabilization of a functional tertiary structure as demonstrated for rhodopsin, β-adrenergic and muscarinic receptors. A cysteine in the C-terminal region conserved in many of the G protein coupled receptors may be a membrane anchoring palmitoylation site as demonstrated for rhodopsin and the β₂-adrenergic receptors. An aspartate commonly found in the third transmembrane domain of charged amine-binding receptors is absent, as expected in these peptide hormone receptors.

[0104] Northern blot analysis reveals that the CCK_(A) receptor cDNA hybridizes to a single poly A+ RNA of 2.7 Kb from pancreas and AR42-J cells and 4.4 Kb from guinea pig gallbladder, but not to rat brain, striated muscle, liver, and kidney. The absence of Northern blot hybridization to rat brain is not surprising for such a diverse cellular organ with CCK_(A) receptors localized to only small discreet areas and is consistent with the need to use PCR cloning methods when a large but limited plaque hybridization screening method failed to identify any positive plaques. High stringency Northern blot hybridization to poly A+ RNA from the same tissues using a CCK_(B) receptor cDNA probe revealed a single hybridizing transcript of 2.4 kB with the expected intensity and distribution in rat brainstem, cortex, and AR42-J cells, and absence of hybridization to rat pancreas, striated muscle, liver, and kidney, tissues and cells expressing either rare or no CCK_(B) receptors. The size of the hybridizing transcript was in close agreement with the cloned CCK_(B) receptor cDNA isolated from AR42-J cells.

EXAMPLE 3

[0105] Expression of CCK_(A) and CCK_(B) Receptor cDNAS in Mammalian Cells and Ligand Inhibition Studies

[0106] Two micrograms of PCDL-SRα containing either the CCK_(A) coding region insert subcloned at an Xba l site in the sense orientation or the CCK_(B) insert subcloned at an Eco R1 site in the sense orientation were transfected into a near confluent 100 mm tissue culture plate containing approximately 1×10⁶ COS-7 cells using a DEAE/dextran method. Approximately 48 hours post transfection, the cells were washed twice with phosphate buffered saline (PBS), pH 7.4, 0.1% BSA at 4° C., scraped from the plate in Dulbecco's Modified Eagle's Medium (DMEM), 0.1% BSA, 4° C., centrifuged at 400×G, and resuspended at approximately 3×10⁵ cells per ml in DMEM, 0.1% BSA, 4° C. Five hundred microliters of resuspended cells were incubated for 60 minutes at 37° C. with 50 pM of the radiolabelled hormone ¹²⁵l-Bolton-Hunter-CCK-8 (2200 Ci/mmole) either with or without varying concentrations of unlabelled agonist or antagonist. Cells were subsequently washed three times with 2 ml PBS, 0.1% BSA, 4° C. by filtration on glass filters (Whatman GF/B) using a suction manifold (Millipore). Filters were assayed for gamma radioactivity (Packard, Auto-Gamma).

[0107] To confirm that the two receptors cloned from rat brain correspond to the CCK_(A) and CCK_(B) receptor subtypes, ligand binding dose inhibition studies were performed. COS-7 cells transfected with the full length cDNA inserts of either CCK_(A) (FIG. 1, SEQ ID NO:13) or CCK_(B) (FIG. 2, SEQ ID NO:15) subcloned into the vector, PCDL-SRα (at the Xba1 site), were incubated with the radiolabelled ligand, ¹²⁵I-BH-CCK-8, alone or in the presence of increasing concentrations of unlabelled CCK receptor agonists or antagonists. Studies with COS-7 cells transfected with the vector containing the CCK_(A) receptor cDNA insert showed that radiolabelled ¹²⁵I-CCK-8 binding inhibition by CCK-8 was about 1000-10,000 fold, or preferably about 3000 fold more potent than gastrin-17-I, and that the CCK_(A) receptor specific antagonist, L-364,718 was about equally potent to CCK-8, and about 30-100 fold more potent than the CCK_(B) receptor specific antagonist, L-365,260.

[0108] Studies with COS-7 cells transfected with the vector containing the CCK_(B) receptor cDNA insert showed that CCK-8 was only about 3-10 fold more potent than Gastrin-17-I, and that the CCK_(B) receptor specific antagonist, L-365,260 was about 10-100 fold more potent than the CCK_(A) receptor specific antagonist, L-364,718 at inhibiting ¹²⁵I-BH-CCK-8 binding. These results agree closely with previous pharmacological binding studies of CCK_(A) and CCK_(B) receptors from rat brain and support the classification of these cloned receptors from rat brain as CCK_(A) and CCK_(B) subtypes.

[0109] It was demonstrated that DNA molecules encoding CCK receptor proteins can be obtained by employing nucleotide sequences encoding CCK_(A) and CCK_(B) receptor proteins as identified by the present invention as probes to isolate from other species such nucleotide molecules encoding CCK receptor protein. Using the methods described above, DNA molecules encoding guinea pig CCK_(A) and CCK_(B) receptor proteins were isolated, whose sequences are provided in FIGS. 6 (SEQ ID NOS. 22 and 23) and 9 (SEQ ID NOS. 25 and 26), respectively.

EXAMPLE 4

[0110] Construction of a Guinea Pig Gallbladder cDNA Library and Isolation of CCK_(A) and CCK_(B) Receptor cDNA Clones

[0111] Male Hartley guinea pigs (150-175 g) were obtained from the Small animal section, Veterinary Resources Branch, National Institutes of Health, Bethesda, Md. Guinea pig pancreases and gallbladders were immediately snap frozen in liquid nitrogen. Total RNA was extracted using a low temperature guanidine isothiocyanate/guanidine hydrochloride method (Han et al., supra). Poly (A)+ RNA was isolated using oligo dT cellulose. Oligo dT primed cDNA>2 kb was size selected by agarose gel electrophoresis, electroeluted, adapted with ECo R1, ligated into lambda gt 10 arms and in vitro packaged using established methods. Approximately 8×10⁵ plaques were screened under high stringency conditions with a ³²P-labelled, randomly primed probe generated from the rat CCK_(A) or the rat CCK_(B) receptor coding regions to obtain the guinea pig CCK_(A) or CCK_(B) receptors, respectively. Duplicate filters were washed once at room temperature for 5 minutes in 2×standard saline citrate (SSC; 2×SSC=300 mM NaCl/3mM sodium citrate and 0.1% SDS) and three times at 55° C. for 20 minutes in 0.1×SSC and 0.1% SDS, dried and autoradiographed for 2 days using. Positive hybridizing clones were plaque purified using established methods.

EXAMPLE 5

[0112] Isolation of Human CCK_(B) Receptor cDNA

[0113] The nucleotide and deduced amino acid sequences of the human CCK_(B) receptor cDNA (FIG. 12, SEQ ID NOS 28 and 29), found to be identical for both brain and stomach, were obtained according to the following method. A human temporal cortex oligo d(T)/random-primed cDNA library, in λ-phage vector, DR 2 (Clontech, Palo Alto, Calif.; catalogue #HL1143), was screened under low stringency conditions (three 30-minute washes in 2×SSC (0.015 saline sodium citrate, 0.15 M NaCl), 0.1% SDS (sodium dodecyl sulfate) at 37° C.) with a ³²P-labelled, random-primed probe derived from the rat CCK_(B) receptor cDNA. The longest clone, Hu-B-10, provided the sequence of nucleotides 281-1969.

[0114] The initial portion of the sequence, nucleotides 1-280, was obtained by the polymerase chain reaction using the degenerate sense primer, (SEQ ID NO:10) 5′-GGAG/CC/TTCA/GG/CA/TGGA/GGCCATGGA-3′. This degenerate primer was derived from the rat and guinea pig CCK_(B) receptor cDNA sequences. The antisense primer used, (SEQ ID NO:11) 5′-GGGCCAGCGATGCACGCACTG-3, was obtained from the Hu-B-10 cDNA sequence described above. The target DNA for PCR was human stomach cDNA prepared from oligo d(T)-primed mRNA, according to the method described by Wank et al., PNAS USA 89: 3125 (1992).

[0115] A full-length cDNA coding region sequence and partial 3′ untranslated sequence of the human CCK_(B) receptor was obtained as a single PCR product using the above degenerate sense primer (SEQ ID NO:10) 5′-GGAG/CC/TTCA/GG/CA/TGGA/GGCCATGGA-3′) plus an additional 5′-15-basepair sequence and a different antisense primer, (SEQ ID NO: 12) 5′-ACTGACTAGTCTAGAGCTTTGGGTGTTGGTTTCCTG-3′ (containing a 5′ cap sequence and a Xba1 restriction sequence). The 5′-15-basepair sequence was comprised of a cap sequence followed by an Xba1 restriction sequence. The full-length sequence and partial 3′ untranslated sequence was made from these primers, digested with Xba1 endonuclease, and subcloned into PCDL-SRα vector and subcloned into COS-7 cells. The pharmacology exhibited by the expressed hCCK_(B) protein was similar to that of guinea pig and rat CCK_(B) receptors, as discussed above (see FIG. 4, bottom panel and FIG. 11).

EXAMPLE 6

[0116] Isolation of Human CCK_(A) Receptor cDNA

[0117] A [³²P]-labelled rat CCK_(A) receptor probe was used to screen a human placental genomic library in λ FIX II vector under conditions of high stringency (0.1×SSC, 42° C.). Screening of approximately 7.5×10⁵ clones resulted in 9 plaque purified clones. PCR amplification of two of these clones using primers derived from the rat CCK_(A) receptor resulted in products highly homologous to the 5′ and 3′ untranslated regions of the rat CCK_(A) receptor cDNA sequence. Primers derived from this new human genomic sequence, 5′GGCAGGTTGCATCTGCGAGAC3′ and 5′CGTTCTTTCTTCTCTGCCTCC3′, were used in PCR cloning of a 1446 basepair cDNA product (nucleotides 54-1500 of FIG. 13) from a human gallbladder cDNA library. This human cDNA sequence contained a single long open reading frame encoding a unique 428 amino acid protein having 91% and 92% homology to the rat and guinea pig CCK_(A) receptors, respectively. Hydropathy analysis revealed seven regions of hydrophobic residues that correspond to putative transmembrane spanning regions expected for members of the G-protein-coupled superfamily of receptors. Similar to the rat, the sequence allows for three potential N-linked glycosylation sites and 4 potential protein kinase C phosphorylation sites.

[0118] Expression of Human CCK_(A) Receptors in Mammalian Cells and Ligand Inhibition Studies

[0119] The human CCK_(A) receptor cDNA clone was subcloned in the mammalian expression vector PCDL-SRα and transfected into COS 7 cells using DEAE/dextran. Transient expression of cell surface receptors was assayed 48 hours post transfection for binding of ¹²⁵I-Bolton-Hunter labelled CCK-8 (¹²⁵I-BH-CCK).

[0120]¹²⁵I-BH-CCK binding was specific and saturable. CCK-8 inhibited binding with high potency (IC50=10 nm) and was greater than 1000 fold more potent than gastrin-17-I. The CCK_(A) receptor selective antagonist L-364,718 inhibited ¹²⁵I-BH-CCK binding with high potency (IC50=1 nM) and was greater than 30-fold more potent than the CCK_(B) receptor selective antagonist, L-365,260. These studies demonstrated that the cDNA cloned from human gallbladder has selective high affinity for sulfated CCK-8 and for the selective CCK_(A) antagonist L-364,718. These studies confirmed that this receptor is a CCK_(A) subtype.

[0121] Northern hybridization using the human CCK_(A) receptor cDNA as a [³²P]-labelled probe identified a 5 Kb hybridizing transcript in the human gallbladder. These results describe for the first time the molecular cloning of the human CCK_(A) receptor. This knowledge will enhance the understanding of the distribution, pharmacology and physiologic role of CCK_(A) receptor in humans.

[0122] The CCK family of peptides interact with at least two receptor subtypes widely distributed throughout the gastrointestinal and nervous systems with some cells possessing both subtypes. The present results should allow better assignment of CCK receptor subtype distribution and function on the basis of such studies as in situ hybridization, cloning of other subtypes using low stringency hybridization methods, production of large quantities of pure receptor for immunization and screening of new more potent and selective agonists and antagonists. This should ultimately allow targeting of therapy to diseased organs of the gastrointestinal and nervous systems while sparing uninvolved organs which possess different CCK subtypes.

[0123] As will be apparent to those skilled in the art in which the invention is addressed, the present invention may be embodied in forms other than those specifically disclosed above without departing from the spirit or essential characteristics of the invention. The particular embodiments of the present invention, described above, are therefore to be considered in all respects as illustrative and not restrictive. The scope of the present invention is as set forth in the appended claims rather than being limited to the foregoing examples.

1 32 22 base pairs nucleic acid single linear misc_difference replace(6, “”) /note= “N at position 6 represents Inosine” misc_difference replace(14, “”) /note= “N at position 14 represents Inosine” 1 ATGCCNABAA YCTNATHCCN AA 22 17 base pairs nucleic acid single linear YES 2 CCRTCRCTRT CYTCRTA 17 17 base pairs nucleic acid single linear YES 3 CCRTCDGART CYTCRTA 17 21 base pairs nucleic acid single linear 4 GCCAGCCAGA AGAAATCTGC C 21 21 base pairs nucleic acid single linear 5 AGCCGAGCAC TGGCAGCAGC A 21 36 base pairs nucleic acid single linear 6 ACTGACTAGT CTAGATCAGC TGCCAACCTG ATAGCC 36 37 base pairs nucleic acid single linear 7 ACTGACTAGT CTAGATAATA CGACTCACTA TAGGGCG 37 36 base pairs nucleic acid single linear 8 ACTGACTAGT CTAGAAATGC TTGCCCAGAT GCTCTG 36 36 base pairs nucleic acid single linear YES 9 ACTGACTAGT CTAGACAGTG GACCAGGTGG AGTTCA 36 21 base pairs nucleic acid single linear 10 GGASYTCRSW GGRGCCATGG A 21 21 base pairs nucleic acid single linear YES 11 GGGCCAGCGA TGCACGCACT G 21 36 base pairs nucleic acid single linear YES 12 ACTGACTAGT CTAGAGCTTT GGGTGTTGGT TTCCTG 36 1506 base pairs nucleic acid double linear cDNA rat pancreatic CCKA receptor CDS 154..1488 13 CCGCAATGCT TGCCCAGATG CTCTGAGAAT GGCGAACTCA AGTTGCCTTT AGGAATGGCT 60 GCAAAGCCCA CACCTGGAAA TCTCCCCCTC CCTGCTCCTC CACGGCAGGT TGCATTTGGG 120 AGACCCTGTG ATCATTAGAG GAGAGAGACA GGA ATG AGC CAT TCA CCA GCT CGC 174 Met Ser His Ser Pro Ala Arg 1 5 CAG CAC TTG GTA GAA AGC AGC AGG ATG GAC GTG GTC GAC AGC CTT CTT 222 Gln His Leu Val Glu Ser Ser Arg Met Asp Val Val Asp Ser Leu Leu 10 15 20 ATG AAT GGG AGC AAC ATC ACT CCC CCC TGT GAA CTC GGA CTG GAA AAT 270 Met Asn Gly Ser Asn Ile Thr Pro Pro Cys Glu Leu Gly Leu Glu Asn 25 30 35 GAG ACG CTT TTC TGC TTG GAT CAA CCT CAA CCT TCA AAA GAG TGG CAG 318 Glu Thr Leu Phe Cys Leu Asp Gln Pro Gln Pro Ser Lys Glu Trp Gln 40 45 50 55 TCT GCA CTG CAG ATT CTC CTG TAC TCC ATC ATA TTC CTT CTC AGT GTG 366 Ser Ala Leu Gln Ile Leu Leu Tyr Ser Ile Ile Phe Leu Leu Ser Val 60 65 70 CTG GGG AAC ACG CTG GTT ATA ACG GTG CTG ATT CGA AAC AAG AGG ATG 414 Leu Gly Asn Thr Leu Val Ile Thr Val Leu Ile Arg Asn Lys Arg Met 75 80 85 CGG ACG GTC ACC AAC ATC TTC CTG CTG TCC CTG GCT GTC AGT GAC CTC 462 Arg Thr Val Thr Asn Ile Phe Leu Leu Ser Leu Ala Val Ser Asp Leu 90 95 100 ATG CTC TGC CTC TTC TGC ATG CCG TTC AAC CTC ATC CCC AAC CTG CTC 510 Met Leu Cys Leu Phe Cys Met Pro Phe Asn Leu Ile Pro Asn Leu Leu 105 110 115 AAG GAT TTC ATC TTC GGA AGT GCC GTG TGC AAG ACT ACC ACC TAC TTC 558 Lys Asp Phe Ile Phe Gly Ser Ala Val Cys Lys Thr Thr Thr Tyr Phe 120 125 130 135 ATG GGC ACT TCC GTG AGC GTT TCC ACC TTC AAC CTG GTA GCC ATC TCT 606 Met Gly Thr Ser Val Ser Val Ser Thr Phe Asn Leu Val Ala Ile Ser 140 145 150 CTG GAG AGA TAT GGC GCC ATC TGC AGA CCC CTA CAG TCC CGC GTC TGG 654 Leu Glu Arg Tyr Gly Ala Ile Cys Arg Pro Leu Gln Ser Arg Val Trp 155 160 165 CAA ACA AAG TCC CAT GCT TTG AAG GTC ATC GCT GCC ACC TGG TGC CTC 702 Gln Thr Lys Ser His Ala Leu Lys Val Ile Ala Ala Thr Trp Cys Leu 170 175 180 TCC TTT ACC ATC ATG ACT CCG TAC CCC ATT TAC AGC AAC TTG GTG CCT 750 Ser Phe Thr Ile Met Thr Pro Tyr Pro Ile Tyr Ser Asn Leu Val Pro 185 190 195 TTT ACT AAA AAT AAT AAC CAG ACG GCG AAC ATG TGC CGC TTC CTG TTG 798 Phe Thr Lys Asn Asn Asn Gln Thr Ala Asn Met Cys Arg Phe Leu Leu 200 205 210 215 CCA AGT GAC GCT ATG CAG CAG TCC TGG CAA ACA TTC CTG CTA CTC ATC 846 Pro Ser Asp Ala Met Gln Gln Ser Trp Gln Thr Phe Leu Leu Leu Ile 220 225 230 CTC TTT CTT CTC CCT GGG ATT GTG ATG GTG GTG GCC TAC GGG TTG ATC 894 Leu Phe Leu Leu Pro Gly Ile Val Met Val Val Ala Tyr Gly Leu Ile 235 240 245 TCT CTG GAA CTC TAC CAA GGA ATC AAA TTT GAT GCC AGC CAG AAG AAA 942 Ser Leu Glu Leu Tyr Gln Gly Ile Lys Phe Asp Ala Ser Gln Lys Lys 250 255 260 TCT GCC AAA GAG AAG AAG CCG AGC ACT GGC AGC AGC ACC CGA TAT GAG 990 Ser Ala Lys Glu Lys Lys Pro Ser Thr Gly Ser Ser Thr Arg Tyr Glu 265 270 275 GAT AGT GAT GGC TGT TAC TTG CAG AAG TCC CGG CCC CCG AGG AAG CTG 1038 Asp Ser Asp Gly Cys Tyr Leu Gln Lys Ser Arg Pro Pro Arg Lys Leu 280 285 290 295 GAG CTT CAG CAG CTG TCT AGC GGC AGC GGT GGC AGC AGA CTC AAC CGG 1086 Glu Leu Gln Gln Leu Ser Ser Gly Ser Gly Gly Ser Arg Leu Asn Arg 300 305 310 ATC AGG AGC AGC AGT TCA GCT GCC AAC CTG ATA GCC AAG AAG CGC GTG 1134 Ile Arg Ser Ser Ser Ser Ala Ala Asn Leu Ile Ala Lys Lys Arg Val 315 320 325 ATC CGC ATG CTC ATT GTC ATC GTG GTC CTC TTC TTC CTG TGC TGG ATG 1182 Ile Arg Met Leu Ile Val Ile Val Val Leu Phe Phe Leu Cys Trp Met 330 335 340 CCC ATC TTC AGC GCC AAC GCC TGG CGG GCA TAT GAC ACG GTT TCT GCC 1230 Pro Ile Phe Ser Ala Asn Ala Trp Arg Ala Tyr Asp Thr Val Ser Ala 345 350 355 GAG AAG CAC CTC TCA GGG ACT CCC ATC TCC TTC ATC CTC CTC CTC TCC 1278 Glu Lys His Leu Ser Gly Thr Pro Ile Ser Phe Ile Leu Leu Leu Ser 360 365 370 375 TAC ACC TCC TCC TGT GTT AAC CCC ATC ATC TAT TGC TTC ATG AAC AAA 1326 Tyr Thr Ser Ser Cys Val Asn Pro Ile Ile Tyr Cys Phe Met Asn Lys 380 385 390 CGC TTT CGC CTG GGC TTC ATG GCC ACC TTC CCT TGT TGC CCG AAT CCC 1374 Arg Phe Arg Leu Gly Phe Met Ala Thr Phe Pro Cys Cys Pro Asn Pro 395 400 405 GGT CCC CCA GGG GTG AGA GGA GAG GTG GGA GAG GAG GAG GAT GGG AGG 1422 Gly Pro Pro Gly Val Arg Gly Glu Val Gly Glu Glu Glu Asp Gly Arg 410 415 420 ACC ATA AGG GCA TTG CTG TCC AGG TAT TCC TAC AGC CAC ATG AGC ACC 1470 Thr Ile Arg Ala Leu Leu Ser Arg Tyr Ser Tyr Ser His Met Ser Thr 425 430 435 TCT GCT CCA CCC CCC TGAACTCCAC CTGGTCCACT G 1506 Ser Ala Pro Pro Pro 440 445 444 amino acids amino acid linear protein 14 Met Ser His Ser Pro Ala Arg Gln His Leu Val Glu Ser Ser Arg Met 1 5 10 15 Asp Val Val Asp Ser Leu Leu Met Asn Gly Ser Asn Ile Thr Pro Pro 20 25 30 Cys Glu Leu Gly Leu Glu Asn Glu Thr Leu Phe Cys Leu Asp Gln Pro 35 40 45 Gln Pro Ser Lys Glu Trp Gln Ser Ala Leu Gln Ile Leu Leu Tyr Ser 50 55 60 Ile Ile Phe Leu Leu Ser Val Leu Gly Asn Thr Leu Val Ile Thr Val 65 70 75 80 Leu Ile Arg Asn Lys Arg Met Arg Thr Val Thr Asn Ile Phe Leu Leu 85 90 95 Ser Leu Ala Val Ser Asp Leu Met Leu Cys Leu Phe Cys Met Pro Phe 100 105 110 Asn Leu Ile Pro Asn Leu Leu Lys Asp Phe Ile Phe Gly Ser Ala Val 115 120 125 Cys Lys Thr Thr Thr Tyr Phe Met Gly Thr Ser Val Ser Val Ser Thr 130 135 140 Phe Asn Leu Val Ala Ile Ser Leu Glu Arg Tyr Gly Ala Ile Cys Arg 145 150 155 160 Pro Leu Gln Ser Arg Val Trp Gln Thr Lys Ser His Ala Leu Lys Val 165 170 175 Ile Ala Ala Thr Trp Cys Leu Ser Phe Thr Ile Met Thr Pro Tyr Pro 180 185 190 Ile Tyr Ser Asn Leu Val Pro Phe Thr Lys Asn Asn Asn Gln Thr Ala 195 200 205 Asn Met Cys Arg Phe Leu Leu Pro Ser Asp Ala Met Gln Gln Ser Trp 210 215 220 Gln Thr Phe Leu Leu Leu Ile Leu Phe Leu Leu Pro Gly Ile Val Met 225 230 235 240 Val Val Ala Tyr Gly Leu Ile Ser Leu Glu Leu Tyr Gln Gly Ile Lys 245 250 255 Phe Asp Ala Ser Gln Lys Lys Ser Ala Lys Glu Lys Lys Pro Ser Thr 260 265 270 Gly Ser Ser Thr Arg Tyr Glu Asp Ser Asp Gly Cys Tyr Leu Gln Lys 275 280 285 Ser Arg Pro Pro Arg Lys Leu Glu Leu Gln Gln Leu Ser Ser Gly Ser 290 295 300 Gly Gly Ser Arg Leu Asn Arg Ile Arg Ser Ser Ser Ser Ala Ala Asn 305 310 315 320 Leu Ile Ala Lys Lys Arg Val Ile Arg Met Leu Ile Val Ile Val Val 325 330 335 Leu Phe Phe Leu Cys Trp Met Pro Ile Phe Ser Ala Asn Ala Trp Arg 340 345 350 Ala Tyr Asp Thr Val Ser Ala Glu Lys His Leu Ser Gly Thr Pro Ile 355 360 365 Ser Phe Ile Leu Leu Leu Ser Tyr Thr Ser Ser Cys Val Asn Pro Ile 370 375 380 Ile Tyr Cys Phe Met Asn Lys Arg Phe Arg Leu Gly Phe Met Ala Thr 385 390 395 400 Phe Pro Cys Cys Pro Asn Pro Gly Pro Pro Gly Val Arg Gly Glu Val 405 410 415 Gly Glu Glu Glu Asp Gly Arg Thr Ile Arg Ala Leu Leu Ser Arg Tyr 420 425 430 Ser Tyr Ser His Met Ser Thr Ser Ala Pro Pro Pro 435 440 2243 base pairs nucleic acid double linear cDNA rat brain CCKB receptor CDS 136..1494 15 TGACCCTGCT TGCTCAACTC TACGTCTTGT TTCGTTTTCT GTTCTGCGCC GTTACAGATC 60 CAAGCTCCTC GAGCCCGGGC TGCAGGAATT CTGCGGCCGC CGCTTAGCAG AGCTAAGTGG 120 GACTTCACTG GAGCC ATG GAG CTG CTC AAG CTG AAC CGC AGC GTG CAG GGA 171 Met Glu Leu Leu Lys Leu Asn Arg Ser Val Gln Gly 1 5 10 CCA GGA CCC GGG TCG GGG TCT TCT TTG TGC CGC CCG GGT GTC TCC CTT 219 Pro Gly Pro Gly Ser Gly Ser Ser Leu Cys Arg Pro Gly Val Ser Leu 15 20 25 CTC AAC AGC AGT AGT GCC GGG AAC CTC AGC TGT GAC CCC CCT CGT ATC 267 Leu Asn Ser Ser Ser Ala Gly Asn Leu Ser Cys Asp Pro Pro Arg Ile 30 35 40 CGC GGA ACC GGG ACC AGA GAA TTG GAG ATG GCG ATT AGA ATC ACC CTT 315 Arg Gly Thr Gly Thr Arg Glu Leu Glu Met Ala Ile Arg Ile Thr Leu 45 50 55 60 TAT GCA GTG ATC TTT CTG ATG AGT GTT GGC GGA AAC GTG CTC ATC ATC 363 Tyr Ala Val Ile Phe Leu Met Ser Val Gly Gly Asn Val Leu Ile Ile 65 70 75 GTG GTC CTG GGA CTG AGC CGA CGC CTA AGA ACG GTC ACC AAC GCC TTC 411 Val Val Leu Gly Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe 80 85 90 CTG CTC TCC CTG GCA GTC AGC GAC CTC CTG CTG GCC GTG GCT TGC ATG 459 Leu Leu Ser Leu Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met 95 100 105 CCC TTC ACA CTC CTG CCC AAC CTC ATG GGC ACA TTC ATC TTC GGC ACA 507 Pro Phe Thr Leu Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr 110 115 120 GTC ATC TGC AAG GCC ATT TCC TAC CTC ATG GGG GTA TCA GTG AGT GTA 555 Val Ile Cys Lys Ala Ile Ser Tyr Leu Met Gly Val Ser Val Ser Val 125 130 135 140 TCC ACT CTA AAT CTC GTG GCC ATA GCC CTG GAG CGA TAC AGC GCC ATC 603 Ser Thr Leu Asn Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile 145 150 155 TGC CGA CCA CTG CAA GCA CGA GTA TGG CAA ACA CGC TCC CAC GCA GCT 651 Cys Arg Pro Leu Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala 160 165 170 CGG GTG ATC TTA GCC ACG TGG CTG CTG TCT GGA CTG CTT ATG GTA CCC 699 Arg Val Ile Leu Ala Thr Trp Leu Leu Ser Gly Leu Leu Met Val Pro 175 180 185 TAC CCT GTG TAC ACC ATG GTA CAG CCA GTG GGA CCT CGA GTG CTG CAG 747 Tyr Pro Val Tyr Thr Met Val Gln Pro Val Gly Pro Arg Val Leu Gln 190 195 200 TGC ATG CAT CGC TGG CCC AGT GCA CGT GTC CAA CAA ACC TGG TCC GTG 795 Cys Met His Arg Trp Pro Ser Ala Arg Val Gln Gln Thr Trp Ser Val 205 210 215 220 CTA CTG CTA CTG CTT TTG TTC TTC ATC CCG GGT GTG GTT ATT GCG GTG 843 Leu Leu Leu Leu Leu Leu Phe Phe Ile Pro Gly Val Val Ile Ala Val 225 230 235 GCC TAT GGA CTC ATC TCC CGC GAA CTC TAC CTA GGA CTC CAC TTT GAT 891 Ala Tyr Gly Leu Ile Ser Arg Glu Leu Tyr Leu Gly Leu His Phe Asp 240 245 250 GGT GAA AAT GAC AGC GAG ACC CAA AGC CGG GCC CGA AAC CAA GGG GGC 939 Gly Glu Asn Asp Ser Glu Thr Gln Ser Arg Ala Arg Asn Gln Gly Gly 255 260 265 CTG CCG GGT GGG GCA GCA CCA GGG CCT GTC CAC CAG AAC GGG GGC TGC 987 Leu Pro Gly Gly Ala Ala Pro Gly Pro Val His Gln Asn Gly Gly Cys 270 275 280 CGG CCT GTA ACC AGC GTA GCT GGG GAA GAC AGT GAT GGC TGC TGT GTG 1035 Arg Pro Val Thr Ser Val Ala Gly Glu Asp Ser Asp Gly Cys Cys Val 285 290 295 300 CAA CTT CCG CGT TCC CGA CTG GAG ATG ACA ACG CTA ACC ACA CCC ACT 1083 Gln Leu Pro Arg Ser Arg Leu Glu Met Thr Thr Leu Thr Thr Pro Thr 305 310 315 CCT GGG CCA GTC CCT GGC CCT CGG CCC AAC CAG GCC AAG CTG CTG GCT 1131 Pro Gly Pro Val Pro Gly Pro Arg Pro Asn Gln Ala Lys Leu Leu Ala 320 325 330 AAG AAG CGG GTG GTG CGA ATG CTG CTA GTG ATT GTT TTG CTT TTC TTC 1179 Lys Lys Arg Val Val Arg Met Leu Leu Val Ile Val Leu Leu Phe Phe 335 340 345 CTG TGT TGG CTG CCA GTG TAC AGC GTC AAC ACG TGG CGC GCC TTC GAT 1227 Leu Cys Trp Leu Pro Val Tyr Ser Val Asn Thr Trp Arg Ala Phe Asp 350 355 360 GGC CCA GGC GCA CAA CGA GCA CTC TCA GGG GCC CCT ATC TCT TTC ATC 1275 Gly Pro Gly Ala Gln Arg Ala Leu Ser Gly Ala Pro Ile Ser Phe Ile 365 370 375 380 CAC TTG CTG AGC TAC GTC TCT GCT TGT GTC AAC CCC CTG GTC TAC TGT 1323 His Leu Leu Ser Tyr Val Ser Ala Cys Val Asn Pro Leu Val Tyr Cys 385 390 395 TTC ATG CAC CGC CGC TTC CGC CAG GCC TGC CTG GAC ACA TGT GCC CGC 1371 Phe Met His Arg Arg Phe Arg Gln Ala Cys Leu Asp Thr Cys Ala Arg 400 405 410 TGT TGC CCA CGC CCT CCA CGA GCT CGC CCA CAG CCT CTT CCA GAT GAG 1419 Cys Cys Pro Arg Pro Pro Arg Ala Arg Pro Gln Pro Leu Pro Asp Glu 415 420 425 GAT CCT CCT ACC CCC TCC ATC GCT TCG CTG TCC AGG CTA AGC TAT ACC 1467 Asp Pro Pro Thr Pro Ser Ile Ala Ser Leu Ser Arg Leu Ser Tyr Thr 430 435 440 ACC ATC AGC ACA CTG GGG CCT GGC TGAGGGGTTG GGAGATTGGA GAAAGAGACA 1521 Thr Ile Ser Thr Leu Gly Pro Gly 445 450 AGATACATAA TTACTATCAA ATGACCCATC CAAACACATA AGAAACAAAA TTCAGAATTA 1581 ATCAGGTGAA CACCCAACAC CATGGACAGA CCCCTACACA CAGAAAATAG TATCTTTGCT 1641 GCCCTACCTG AAACAGATAG GAGTCTCATA GGAAAGGAGG CTCACTTCTG ATAAGGGGCT 1701 GAGTCCCTTC CTAGACATCT TGCACTGACC CCATTACATG GACAGACACA AGGTCCGTAG 1761 CAGTAAACTT TACCTATAAA GGGGAACTCT GACAAGGGCT GATTGGCTCC TCATATGAAC 1821 ATATTACTGA CACTATTCTG TAGTGCCCAT AGCCTAGTGC AGAAGTGACT TAGGACATTG 1881 TGGCTGTTCC CGTTTGACTT CATTATTGCC TTCCTCATCC AGCACTGAAA TTATCAACCA 1941 CACGCCTTTC ACCTTTCGGA GCTGCCGATC GTTCAGCACT GAAAAGTCCC CCCCCCCCAC 2001 TCCTTTCCAT TGGAGACTGT GGAAAGTCCT CTTCCCTCCT GCCTCTCCTC CCTCACCAGA 2061 CCACATCATA AAAGGATAAG TGACTTAGTG TCCTCCTGGA CTTCTTGAGG TAGGTGAACA 2121 GGTGTGGTTT ATGGGAAGCT TCTTCATTTA TTGGCTCCCA TGACTAATCT ACCCCATATC 2181 CAACCTTGTG CAAAAAGGCC AGGGTATGAA GATAGGGATG AGCGTACCCT CTCTTGGTTG 2241 TC 2243 452 amino acids amino acid linear protein 16 Met Glu Leu Leu Lys Leu Asn Arg Ser Val Gln Gly Pro Gly Pro Gly 1 5 10 15 Ser Gly Ser Ser Leu Cys Arg Pro Gly Val Ser Leu Leu Asn Ser Ser 20 25 30 Ser Ala Gly Asn Leu Ser Cys Asp Pro Pro Arg Ile Arg Gly Thr Gly 35 40 45 Thr Arg Glu Leu Glu Met Ala Ile Arg Ile Thr Leu Tyr Ala Val Ile 50 55 60 Phe Leu Met Ser Val Gly Gly Asn Val Leu Ile Ile Val Val Leu Gly 65 70 75 80 Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe Leu Leu Ser Leu 85 90 95 Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met Pro Phe Thr Leu 100 105 110 Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr Val Ile Cys Lys 115 120 125 Ala Ile Ser Tyr Leu Met Gly Val Ser Val Ser Val Ser Thr Leu Asn 130 135 140 Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile Cys Arg Pro Leu 145 150 155 160 Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala Arg Val Ile Leu 165 170 175 Ala Thr Trp Leu Leu Ser Gly Leu Leu Met Val Pro Tyr Pro Val Tyr 180 185 190 Thr Met Val Gln Pro Val Gly Pro Arg Val Leu Gln Cys Met His Arg 195 200 205 Trp Pro Ser Ala Arg Val Gln Gln Thr Trp Ser Val Leu Leu Leu Leu 210 215 220 Leu Leu Phe Phe Ile Pro Gly Val Val Ile Ala Val Ala Tyr Gly Leu 225 230 235 240 Ile Ser Arg Glu Leu Tyr Leu Gly Leu His Phe Asp Gly Glu Asn Asp 245 250 255 Ser Glu Thr Gln Ser Arg Ala Arg Asn Gln Gly Gly Leu Pro Gly Gly 260 265 270 Ala Ala Pro Gly Pro Val His Gln Asn Gly Gly Cys Arg Pro Val Thr 275 280 285 Ser Val Ala Gly Glu Asp Ser Asp Gly Cys Cys Val Gln Leu Pro Arg 290 295 300 Ser Arg Leu Glu Met Thr Thr Leu Thr Thr Pro Thr Pro Gly Pro Val 305 310 315 320 Pro Gly Pro Arg Pro Asn Gln Ala Lys Leu Leu Ala Lys Lys Arg Val 325 330 335 Val Arg Met Leu Leu Val Ile Val Leu Leu Phe Phe Leu Cys Trp Leu 340 345 350 Pro Val Tyr Ser Val Asn Thr Trp Arg Ala Phe Asp Gly Pro Gly Ala 355 360 365 Gln Arg Ala Leu Ser Gly Ala Pro Ile Ser Phe Ile His Leu Leu Ser 370 375 380 Tyr Val Ser Ala Cys Val Asn Pro Leu Val Tyr Cys Phe Met His Arg 385 390 395 400 Arg Phe Arg Gln Ala Cys Leu Asp Thr Cys Ala Arg Cys Cys Pro Arg 405 410 415 Pro Pro Arg Ala Arg Pro Gln Pro Leu Pro Asp Glu Asp Pro Pro Thr 420 425 430 Pro Ser Ile Ala Ser Leu Ser Arg Leu Ser Tyr Thr Thr Ile Ser Thr 435 440 445 Leu Gly Pro Gly 450 384 amino acids amino acid linear mouse gastrin-releasing peptide receptor 17 Met Ala Pro Asn Asn Cys Ser His Leu Asn Leu Asp Val Asp Pro Phe 1 5 10 15 Leu Ser Cys Asn Asp Thr Phe Asn Gln Ser Leu Ser Pro Pro Lys Met 20 25 30 Asp Asn Trp Phe His Pro Gly Phe Ile Tyr Val Ile Pro Ala Val Tyr 35 40 45 Gly Leu Ile Ile Val Ile Gly Leu Ile Gly Asn Ile Thr Leu Ile Lys 50 55 60 Ile Phe Cys Thr Val Lys Ser Met Arg Asn Val Pro Asn Leu Phe Ile 65 70 75 80 Ser Ser Leu Ala Leu Gly Asp Leu Leu Leu Leu Val Thr Cys Ala Pro 85 90 95 Val Asp Ala Ser Lys Tyr Leu Ala Asp Arg Trp Leu Phe Gly Arg Ile 100 105 110 Gly Cys Lys Leu Ile Pro Phe Ile Gln Leu Thr Ser Val Gly Val Ser 115 120 125 Val Phe Thr Leu Thr Ala Leu Ser Ala Asp Arg Tyr Lys Ala Ile Val 130 135 140 Arg Pro Met Asp Ile Gln Ala Ser His Ala Leu Met Lys Ile Cys Leu 145 150 155 160 Lys Ala Ala Leu Ile Trp Ile Val Ser Met Leu Leu Ala Ile Pro Glu 165 170 175 Ala Val Phe Ser Asp Leu His Pro Phe His Val Lys Asp Thr Asn Gln 180 185 190 Thr Phe Ile Ser Cys Ala Pro Tyr Pro His Ser Asn Glu Leu His Pro 195 200 205 Lys Ile His Ser Met Ala Ser Phe Leu Val Phe Tyr Val Ile Pro Leu 210 215 220 Ala Ile Ile Ser Val Tyr Tyr Tyr Phe Ile Ala Arg Asn Leu Ile Gln 225 230 235 240 Ser Ala Tyr Asn Leu Pro Val Glu Gly Asn Ile His Val Lys Lys Gln 245 250 255 Ile Glu Ser Arg Lys Arg Leu Ala Lys Thr Val Leu Val Phe Val Gly 260 265 270 Leu Phe Ala Phe Cys Trp Leu Pro Asn His Val Ile Tyr Leu Tyr Arg 275 280 285 Ser Tyr His Tyr Ser Glu Val Asp Thr Ser Met Leu His Phe Val Thr 290 295 300 Ser Ile Cys Ala His Leu Leu Ala Phe Thr Asn Ser Cys Val Asn Pro 305 310 315 320 Phe Ala Leu Tyr Leu Leu Ser Lys Ser Phe Arg Lys Gln Phe Asn Thr 325 330 335 Gln Leu Leu Cys Cys Gln Pro Gly Leu Met Asn Arg Ser His Ser Thr 340 345 350 Gly Arg Ser Thr Thr Cys Met Thr Ser Phe Lys Ser Thr Asn Pro Ser 355 360 365 Ala Thr Phe Ser Leu Ile Asn Arg Asn Ile Cys His Glu Gly Tyr Val 370 375 380 390 amino acids amino acid linear rat neuromedin B receptor 18 Met Pro Pro Arg Ser Leu Pro Asn Leu Ser Leu Pro Thr Glu Ala Ser 1 5 10 15 Glu Ser Glu Leu Glu Pro Glu Val Trp Glu Asn Asp Phe Leu Pro Asp 20 25 30 Ser Asp Gly Thr Thr Ala Glu Leu Val Ile Arg Cys Val Ile Pro Ser 35 40 45 Leu Tyr Leu Ile Ile Ile Ser Val Gly Leu Leu Gly Asn Ile Met Leu 50 55 60 Val Lys Ile Phe Leu Thr Asn Ser Thr Met Arg Ser Val Pro Asn Ile 65 70 75 80 Phe Ile Ser Asn Leu Ala Ala Gly Asp Leu Leu Leu Leu Leu Thr Cys 85 90 95 Val Pro Val Asp Ala Ser Arg Tyr Phe Phe Asp Glu Trp Val Phe Gly 100 105 110 Lys Leu Gly Cys Lys Leu Ile Pro Ala Ile Gln Leu Thr Ser Val Gly 115 120 125 Val Ser Val Phe Thr Leu Thr Ala Leu Ser Ala Asp Arg Tyr Arg Ala 130 135 140 Ile Val Asn Pro Met Asp Met Gln Thr Ser Gly Val Val Leu Trp Thr 145 150 155 160 Ser Leu Lys Ala Val Gly Ile Trp Val Val Ser Val Leu Leu Ala Val 165 170 175 Pro Glu Ala Val Phe Ser Glu Val Ala Arg Ile Gly Ser Ser Asp Asn 180 185 190 Ser Ser Phe Thr Ala Cys Ile Pro Tyr Pro Gln Thr Asp Glu Leu His 195 200 205 Pro Lys Ile His Ser Val Leu Ile Phe Leu Val Tyr Phe Leu Ile Pro 210 215 220 Leu Val Ile Ile Ser Ile Tyr Tyr Tyr His Ile Ala Lys Thr Leu Ile 225 230 235 240 Arg Ser Ala His Asn Leu Pro Gly Glu Tyr Asn Glu His Thr Lys Lys 245 250 255 Gln Met Glu Thr Arg Lys Arg Leu Ala Lys Ile Val Leu Val Phe Val 260 265 270 Gly Cys Phe Val Phe Cys Trp Phe Pro Asn His Ile Leu Tyr Leu Tyr 275 280 285 Arg Ser Phe Asn Tyr Lys Glu Ile Asp Pro Ser Leu Gly His Met Ile 290 295 300 Val Thr Leu Val Ala Arg Val Leu Ser Phe Ser Asn Ser Cys Val Asn 305 310 315 320 Pro Phe Ala Leu Tyr Leu Leu Ser Glu Ser Phe Arg Lys His Phe Asn 325 330 335 Ser Gln Leu Cys Cys Gly Gln Lys Ser Tyr Pro Glu Arg Ser Thr Ser 340 345 350 Tyr Leu Leu Ser Ser Ser Ala Val Arg Met Thr Ser Leu Lys Ser Asn 355 360 365 Ala Lys Asn Val Val Thr Asn Ser Val Leu Leu Asn Gly His Ser Thr 370 375 380 Lys Gln Glu Ile Ala Leu 385 390 369 amino acids amino acid linear rat substance K receptor 19 Met Gly Thr Arg Ala Ile Val Ser Asp Ala Asn Ile Leu Ser Gly Leu 1 5 10 15 Glu Ser Asn Ala Thr Gly Val Thr Ala Phe Ser Met Pro Gly Trp Gln 20 25 30 Leu Ala Leu Trp Ala Thr Ala Tyr Leu Ala Leu Val Leu Val Ala Val 35 40 45 Thr Gly Asn Ala Thr Val Ile Trp Ile Ile Leu Ala His Glu Arg Met 50 55 60 Arg Thr Val Thr Asn Tyr Phe Ile Ile Asn Leu Ala Leu Ala Asp Leu 65 70 75 80 Cys Met Ala Ala Phe Asn Ala Thr Phe Asn Phe Ile Tyr Ala Ser His 85 90 95 Asn Ile Trp Tyr Phe Gly Arg Ala Phe Cys Tyr Phe Gln Asn Leu Phe 100 105 110 Pro Ile Thr Ala Met Phe Val Ser Ile Tyr Ser Met Thr Ala Ile Ala 115 120 125 Ala Asp Arg Tyr Met Ala Ile Val His Pro Phe Gln Pro Arg Leu Ser 130 135 140 Ala Pro Ser Thr Lys Ala Ile Ile Ala Gly Ile Trp Leu Val Ala Leu 145 150 155 160 Ala Leu Ala Ser Pro Gln Cys Phe Tyr Ser Thr Ile Thr Val Asp Glu 165 170 175 Gly Ala Thr Lys Cys Val Val Ala Trp Pro Asn Asp Asn Gly Gly Lys 180 185 190 Met Leu Leu Leu Tyr His Leu Val Val Phe Val Leu Ile Tyr Phe Leu 195 200 205 Pro Leu Leu Val Met Phe Gly Ala Tyr Ser Val Ile Gly Leu Thr Leu 210 215 220 Trp Lys Arg Ala Val Pro Arg His Gln Ala His Gly Ala Asn Leu Arg 225 230 235 240 His Leu Gln Ala Lys Lys Lys Phe Val Lys Ala Met Val Leu Val Val 245 250 255 Leu Thr Phe Ala Ile Cys Trp Leu Pro Tyr His Leu Tyr Phe Ile Leu 260 265 270 Gly Thr Phe Gln Glu Asp Ile Tyr Tyr His Lys Phe Ile Gln Gln Val 275 280 285 Tyr Leu Ala Leu Phe Trp Leu Ala Met Ser Ser Thr Met Tyr Asn Pro 290 295 300 Ile Ile Tyr Cys Cys Leu Asn His Arg Phe Arg Ser Gly Phe Arg Leu 305 310 315 320 Ala Phe Arg Cys Cys Pro Trp Val Thr Pro Thr Glu Glu Asp Arg Leu 325 330 335 Glu Leu Thr His Thr Pro Ser Leu Ser Arg Arg Val Asn Arg Cys His 340 345 350 Thr Lys Glu Thr Leu Phe Met Thr Gly Asp Met Thr His Ser Glu Ala 355 360 365 Thr 372 amino acids amino acid linear rat substance P receptor 20 Met Asp Asn Val Leu Pro Met Asp Ser Asp Leu Phe Pro Asn Ile Ser 1 5 10 15 Thr Asn Thr Ser Glu Ser Asn Gln Phe Val Gln Pro Thr Trp Gln Ile 20 25 30 Val Leu Trp Ala Ala Ala Tyr Thr Val Ile Val Val Thr Ser Val Val 35 40 45 Gly Asn Val Val Val Ile Trp Ile Ile Leu Ala His Lys Arg Met Arg 50 55 60 Thr Val Thr Asn Tyr Phe Leu Val Asn Leu Ala Phe Ala Glu Ala Cys 65 70 75 80 Met Ala Ala Phe Asn Thr Val Val Asn Phe Thr Tyr Ala Val His Asn 85 90 95 Val Trp Tyr Tyr Gly Leu Phe Tyr Cys Lys Phe His Asn Phe Phe Pro 100 105 110 Ile Ala Ala Leu Phe Ala Ser Ile Tyr Ser Met Thr Ala Val Ala Phe 115 120 125 Asp Arg Tyr Met Ala Ile Ile His Pro Leu Gln Pro Arg Leu Ser Ala 130 135 140 Thr Ala Thr Lys Val Val Ile Phe Val Ile Trp Val Leu Ala Leu Leu 145 150 155 160 Leu Ala Phe Pro Gln Gly Tyr Tyr Ser Thr Thr Glu Thr Met Pro Ser 165 170 175 Arg Val Val Cys Met Ile Glu Trp Pro Glu His Pro Asn Arg Thr Tyr 180 185 190 Glu Lys Ala Tyr His Ile Cys Val Thr Val Leu Ile Tyr Phe Leu Pro 195 200 205 Leu Leu Val Ile Gly Tyr Ala Tyr Thr Val Val Gly Ile Thr Leu Trp 210 215 220 Ala Ser Glu Ile Pro Gly Asp Ser Ser Asp Arg Tyr His Glu Gln Val 225 230 235 240 Ser Ala Lys Arg Lys Val Val Lys Met Met Ile Val Val Val Cys Thr 245 250 255 Phe Ala Ile Cys Trp Leu Pro Phe His Val Phe Phe Leu Leu Pro Tyr 260 265 270 Ile Asn Pro Asp Leu Tyr Leu Lys Lys Phe Ile Gln Gln Val Tyr Leu 275 280 285 Ala Ser Met Trp Leu Ala Met Ser Ser Thr Met Tyr Asn Pro Ile Ile 290 295 300 Tyr Cys Cys Leu Asn Asp Arg Phe Arg Leu Gly Phe Lys His Ala Phe 305 310 315 320 Arg Cys Cys Pro Phe Ile Ser Ala Gly Asp Tyr Glu Gly Leu Glu Met 325 330 335 Lys Ser Thr Arg Tyr Leu Gln Thr Gln Ser Ser Val Tyr Lys Val Ser 340 345 350 Arg Leu Glu Thr Thr Ile Ser Thr Val Val Gly Ala His Glu Glu Glu 355 360 365 Pro Glu Glu Gly 370 411 amino acids amino acid linear 21 Met Ala Ser Val Pro Arg Gly Glu Asn Trp Thr Asp Gly Thr Val Glu 1 5 10 15 Val Gly Thr His Thr Gly Asn Leu Ser Ser Ala Leu Gly Val Thr Glu 20 25 30 Trp Leu Ala Leu Gln Ala Gly Asn Phe Ser Ser Ala Leu Gly Leu Pro 35 40 45 Ala Thr Thr Gln Ala Pro Ser Gln Val Arg Ala Asn Leu Thr Asn Gln 50 55 60 Phe Val Gln Pro Ser Trp Arg Ile Ala Leu Trp Ser Leu Ala Tyr Gly 65 70 75 80 Leu Val Val Ala Val Ala Val Phe Gly Asn Leu Ile Val Ile Trp Ile 85 90 95 Ile Leu Ala His Lys Arg Met Arg Thr Val Thr Asn Tyr Phe Leu Val 100 105 110 Asn Leu Ala Phe Ser Asp Ala Ser Val Ala Ala Phe Asn Thr Leu Ile 115 120 125 Asn Phe Ile Tyr Gly Leu His Ser Glu Trp Tyr Phe Gly Ala Asn Tyr 130 135 140 Cys Arg Phe Gln Asn Phe Phe Pro Ile Thr Ala Val Phe Ala Ser Ile 145 150 155 160 Tyr Ser Met Thr Ala Ile Ala Val Asp Arg Tyr Met Ala Ile Ile Asp 165 170 175 Pro Leu Lys Pro Arg Leu Ser Ala Thr Ala Thr Lys Ile Val Ile Gly 180 185 190 Ser Ile Trp Ile Leu Ala Phe Leu Leu Ala Phe Pro Gln Cys Leu Tyr 195 200 205 Ser Lys Ile Lys Val Met Pro Gly Arg Thr Leu Cys Tyr Val Gln Trp 210 215 220 Pro Glu Gly Pro Lys Gln His Phe Thr Tyr His Ile Ile Val Ile Ile 225 230 235 240 Leu Val Tyr Cys Phe Pro Leu Leu Ile Met Gly Val Thr Tyr Thr Ile 245 250 255 Val Gly Ile Thr Leu Trp Gly Gly Glu Ile Pro Gly Asp Thr Cys Asp 260 265 270 Lys Tyr His Glu Gln Leu Lys Ala Lys Arg Lys Val Val Lys Met Met 275 280 285 Ile Ile Val Val Val Thr Phe Ala Ile Cys Trp Leu Pro Tyr His Val 290 295 300 Tyr Phe Ile Leu Thr Ala Ile Tyr Gln Gln Leu Asn Arg Trp Lys Tyr 305 310 315 320 Ile Gln Gln Val Tyr Leu Ala Ser Phe Trp Leu Ala Met Ser Ser Thr 325 330 335 Met Tyr Asn Pro Ile Ile Tyr Cys Cys Leu Asn Lys Arg Phe Arg Ala 340 345 350 Gly Phe Lys Arg Ala Phe Arg Trp Cys Pro Phe Ile Gln Val Ser Ser 355 360 365 Tyr Asp Glu Leu Glu Leu Lys Thr Thr Arg Phe His Pro Thr Arg Gln 370 375 380 Ser Ser Leu Tyr Thr Val Ser Arg Met Glu Ser Val Thr Val Leu Phe 385 390 395 400 Asp Pro Asn Asp Gly Asp Pro Thr Lys Ser Ser 405 410 1621 base pairs nucleic acid double linear guinea pig gallbladder and pancreas CCKA CDS 205..1497 22 CGCAGGATGC GTGCCCAGCT GGACGGAGGG TAGTGAACTC CAGGTGCCTT TAGGAATGGC 60 TGCAAAAGCC CACACCTGGC AATCACTCTC TGCCTGCCTC TCCCCGGCAG GTTGCATTTG 120 GGAGGCGCTC TGGTCATCAG AGGAATGAGC GTGGAGAGAG CTGTTTGCCA GCCCGCCAGC 180 CCCTGGTGGG AAGCAGAGGC GAGG ATG GAC GTG GTA GAC AGC CTT TTT GTG 231 Met Asp Val Val Asp Ser Leu Phe Val 1 5 AAT GGG AGC AAC ATC ACT TCT GCC TGC GAG CTC GGC TTT GAA AAT GAG 279 Asn Gly Ser Asn Ile Thr Ser Ala Cys Glu Leu Gly Phe Glu Asn Glu 10 15 20 25 ACA CTT TTC TGC TTG GAT CGG CCC CGG CCT TCC AAA GAG TGG CAG CCG 327 Thr Leu Phe Cys Leu Asp Arg Pro Arg Pro Ser Lys Glu Trp Gln Pro 30 35 40 GCG GTG CAG ATT CTC TTG TAT TCC TTG ATA TTC CTG CTC AGC GTG CTG 375 Ala Val Gln Ile Leu Leu Tyr Ser Leu Ile Phe Leu Leu Ser Val Leu 45 50 55 GGA AAC ACG CTG GTA ATC ACG GTG CTG ATT CGG AAC AAG AGG ATG AGG 423 Gly Asn Thr Leu Val Ile Thr Val Leu Ile Arg Asn Lys Arg Met Arg 60 65 70 ACG GTC ACT AAC ATC TTC CTG CTC TCA CTG GCT GTC AGT GAC CTC ATG 471 Thr Val Thr Asn Ile Phe Leu Leu Ser Leu Ala Val Ser Asp Leu Met 75 80 85 CTC TGC CTC TTC TGC ATG CCC TTC AAC CTC ATC CCC AGC CTG CTC AAG 519 Leu Cys Leu Phe Cys Met Pro Phe Asn Leu Ile Pro Ser Leu Leu Lys 90 95 100 105 GAT TTC ATC TTC GGG AGT GCC GTG TGC AAG ACC ACC ACC TAC TTC ATG 567 Asp Phe Ile Phe Gly Ser Ala Val Cys Lys Thr Thr Thr Tyr Phe Met 110 115 120 GGC ACC TCT GTG AGT GTA TCC ACC TTT AAT CTG GTG GCC ATA TCG CTG 615 Gly Thr Ser Val Ser Val Ser Thr Phe Asn Leu Val Ala Ile Ser Leu 125 130 135 GAG AGA TAC GGA GCA ATT TGC AAA CCC TTA CAG TCC CGC GTC TGG CAA 663 Glu Arg Tyr Gly Ala Ile Cys Lys Pro Leu Gln Ser Arg Val Trp Gln 140 145 150 ACA AAG TCG CAT GCT TTG AAG GTG ATT GCT GCT ACC TGG TGC CTC TCC 711 Thr Lys Ser His Ala Leu Lys Val Ile Ala Ala Thr Trp Cys Leu Ser 155 160 165 TTT ACC ATC ATG ACC CCC TAC CCC ATC TAC AGC AAC CTG GTG CCT TTT 759 Phe Thr Ile Met Thr Pro Tyr Pro Ile Tyr Ser Asn Leu Val Pro Phe 170 175 180 185 ACC AAA AAT AAC AAC CAG ACC GGG AAC ATG TGC CGC TTC CTA CTG CCA 807 Thr Lys Asn Asn Asn Gln Thr Gly Asn Met Cys Arg Phe Leu Leu Pro 190 195 200 AAC GAT GTT ATG CAG CAG ACC TGG CAC ACT TTC CTG TTA CTC ATC CTC 855 Asn Asp Val Met Gln Gln Thr Trp His Thr Phe Leu Leu Leu Ile Leu 205 210 215 TTT CTT ATT CCC GGA ATT GTG ATG ATG GTG GCA TAT GGA CTG ATT TCT 903 Phe Leu Ile Pro Gly Ile Val Met Met Val Ala Tyr Gly Leu Ile Ser 220 225 230 CTG GAA CTT TAC CAA GGA ATA AAA TTC GAT GCT ATC CAG AAG AAA TCT 951 Leu Glu Leu Tyr Gln Gly Ile Lys Phe Asp Ala Ile Gln Lys Lys Ser 235 240 245 GCT AAA GAA AGG AAG ACA AGC ACT GGC AGC AGT GGC CCG ATG GAG GAC 999 Ala Lys Glu Arg Lys Thr Ser Thr Gly Ser Ser Gly Pro Met Glu Asp 250 255 260 265 AGT GAT GGG TGT TAC CTG CAG AAG TCC AGG CAC CCC AGA AAG CTG GAG 1047 Ser Asp Gly Cys Tyr Leu Gln Lys Ser Arg His Pro Arg Lys Leu Glu 270 275 280 CTT CGG CAG CTG TCC CCC AGC AGC AGT GGC AGC AAC AGG ATC AAT CGT 1095 Leu Arg Gln Leu Ser Pro Ser Ser Ser Gly Ser Asn Arg Ile Asn Arg 285 290 295 ATC CGG AGC AGC AGC TCC ACC GCC AAC TTG ATG GCC AAA AAG CGG GTG 1143 Ile Arg Ser Ser Ser Ser Thr Ala Asn Leu Met Ala Lys Lys Arg Val 300 305 310 ATC CGC ATG CTC ATC GTC ATT GTG GTC CTC TTC TTC CTG TGC TGG ATG 1191 Ile Arg Met Leu Ile Val Ile Val Val Leu Phe Phe Leu Cys Trp Met 315 320 325 CCC ATC TTC AGC GCC AAT GCC TGG CGG GCA TAC GAC ACC GTC TCT GCC 1239 Pro Ile Phe Ser Ala Asn Ala Trp Arg Ala Tyr Asp Thr Val Ser Ala 330 335 340 345 GAG CGC CAC CTC TCT GGG ACA CCT ATC TCC TTC ATC CTC CTG CTC TCT 1287 Glu Arg His Leu Ser Gly Thr Pro Ile Ser Phe Ile Leu Leu Leu Ser 350 355 360 TAC ACC TCC TCC TGC GTC AAC CCC ATC ATC TAC TGC TTC ATG AAC AAA 1335 Tyr Thr Ser Ser Cys Val Asn Pro Ile Ile Tyr Cys Phe Met Asn Lys 365 370 375 CGA TTC CGT CTT GGC TTC ATG GCC ACC TTC CCC TGC TGT CCC AAC CCA 1383 Arg Phe Arg Leu Gly Phe Met Ala Thr Phe Pro Cys Cys Pro Asn Pro 380 385 390 GGT ACC CCT GGG GTG AGA GGA GAG ATG GGA GAG GAG GAG GAA GGC AGG 1431 Gly Thr Pro Gly Val Arg Gly Glu Met Gly Glu Glu Glu Glu Gly Arg 395 400 405 ACC ACA GGG GCG TCT TTG TCC AGA TAC TCC TAC AGC CAC ATG AGC ACC 1479 Thr Thr Gly Ala Ser Leu Ser Arg Tyr Ser Tyr Ser His Met Ser Thr 410 415 420 425 TCT GCT CCG CCC CCG TGAGCTGGGC CCGGGGCTAC ACAGTACAGC AGGAAGGAGG 1534 Ser Ala Pro Pro Pro 430 CCACGGGAGG AGGAGGAGAA AAGAAAGGAA AGGAGAAAGC AGGAGAAGCA GGAGGAGGCA 1594 GAAGCAAAAG AGAAGGAAGG CCCAGGT 1621 430 amino acids amino acid linear protein 23 Met Asp Val Val Asp Ser Leu Phe Val Asn Gly Ser Asn Ile Thr Ser 1 5 10 15 Ala Cys Glu Leu Gly Phe Glu Asn Glu Thr Leu Phe Cys Leu Asp Arg 20 25 30 Pro Arg Pro Ser Lys Glu Trp Gln Pro Ala Val Gln Ile Leu Leu Tyr 35 40 45 Ser Leu Ile Phe Leu Leu Ser Val Leu Gly Asn Thr Leu Val Ile Thr 50 55 60 Val Leu Ile Arg Asn Lys Arg Met Arg Thr Val Thr Asn Ile Phe Leu 65 70 75 80 Leu Ser Leu Ala Val Ser Asp Leu Met Leu Cys Leu Phe Cys Met Pro 85 90 95 Phe Asn Leu Ile Pro Ser Leu Leu Lys Asp Phe Ile Phe Gly Ser Ala 100 105 110 Val Cys Lys Thr Thr Thr Tyr Phe Met Gly Thr Ser Val Ser Val Ser 115 120 125 Thr Phe Asn Leu Val Ala Ile Ser Leu Glu Arg Tyr Gly Ala Ile Cys 130 135 140 Lys Pro Leu Gln Ser Arg Val Trp Gln Thr Lys Ser His Ala Leu Lys 145 150 155 160 Val Ile Ala Ala Thr Trp Cys Leu Ser Phe Thr Ile Met Thr Pro Tyr 165 170 175 Pro Ile Tyr Ser Asn Leu Val Pro Phe Thr Lys Asn Asn Asn Gln Thr 180 185 190 Gly Asn Met Cys Arg Phe Leu Leu Pro Asn Asp Val Met Gln Gln Thr 195 200 205 Trp His Thr Phe Leu Leu Leu Ile Leu Phe Leu Ile Pro Gly Ile Val 210 215 220 Met Met Val Ala Tyr Gly Leu Ile Ser Leu Glu Leu Tyr Gln Gly Ile 225 230 235 240 Lys Phe Asp Ala Ile Gln Lys Lys Ser Ala Lys Glu Arg Lys Thr Ser 245 250 255 Thr Gly Ser Ser Gly Pro Met Glu Asp Ser Asp Gly Cys Tyr Leu Gln 260 265 270 Lys Ser Arg His Pro Arg Lys Leu Glu Leu Arg Gln Leu Ser Pro Ser 275 280 285 Ser Ser Gly Ser Asn Arg Ile Asn Arg Ile Arg Ser Ser Ser Ser Thr 290 295 300 Ala Asn Leu Met Ala Lys Lys Arg Val Ile Arg Met Leu Ile Val Ile 305 310 315 320 Val Val Leu Phe Phe Leu Cys Trp Met Pro Ile Phe Ser Ala Asn Ala 325 330 335 Trp Arg Ala Tyr Asp Thr Val Ser Ala Glu Arg His Leu Ser Gly Thr 340 345 350 Pro Ile Ser Phe Ile Leu Leu Leu Ser Tyr Thr Ser Ser Cys Val Asn 355 360 365 Pro Ile Ile Tyr Cys Phe Met Asn Lys Arg Phe Arg Leu Gly Phe Met 370 375 380 Ala Thr Phe Pro Cys Cys Pro Asn Pro Gly Thr Pro Gly Val Arg Gly 385 390 395 400 Glu Met Gly Glu Glu Glu Glu Gly Arg Thr Thr Gly Ala Ser Leu Ser 405 410 415 Arg Tyr Ser Tyr Ser His Met Ser Thr Ser Ala Pro Pro Pro 420 425 430 450 amino acids amino acid linear guinea pig CCKA receptor 24 Met Ser Val Glu Arg Ala Val Cys Gln Pro Ala Ser Pro Trp Trp Glu 1 5 10 15 Ala Glu Ala Arg Met Asp Val Val Asp Ser Leu Phe Val Asn Gly Ser 20 25 30 Asn Ile Thr Ser Ala Cys Glu Leu Gly Phe Glu Asn Glu Thr Leu Phe 35 40 45 Cys Leu Asp Arg Pro Arg Pro Ser Lys Glu Trp Gln Pro Ala Val Gln 50 55 60 Ile Leu Leu Tyr Ser Leu Ile Phe Leu Leu Ser Val Leu Gly Asn Thr 65 70 75 80 Leu Val Ile Thr Val Leu Ile Arg Asn Lys Arg Met Arg Thr Val Thr 85 90 95 Asn Ile Phe Leu Leu Ser Leu Ala Val Ser Asp Leu Met Leu Cys Leu 100 105 110 Phe Cys Met Pro Phe Asn Leu Ile Pro Ser Leu Leu Lys Asp Phe Ile 115 120 125 Phe Gly Ser Ala Val Cys Lys Thr Thr Thr Tyr Phe Met Gly Thr Ser 130 135 140 Val Ser Val Ser Thr Phe Asn Leu Val Ala Ile Ser Leu Glu Arg Tyr 145 150 155 160 Gly Ala Ile Cys Lys Pro Leu Gln Ser Arg Val Trp Gln Thr Lys Ser 165 170 175 His Ala Leu Lys Val Ile Ala Ala Thr Trp Cys Leu Ser Phe Thr Ile 180 185 190 Met Thr Pro Tyr Pro Ile Tyr Ser Asn Leu Val Pro Phe Thr Lys Asn 195 200 205 Asn Asn Gln Thr Gly Asn Met Cys Arg Phe Leu Leu Pro Asn Asp Val 210 215 220 Met Gln Gln Thr Trp His Thr Phe Leu Leu Leu Ile Leu Phe Leu Ile 225 230 235 240 Pro Gly Ile Val Met Met Val Ala Tyr Gly Leu Ile Ser Leu Glu Leu 245 250 255 Tyr Gln Gly Ile Lys Phe Asp Ala Ile Gln Lys Lys Ser Ala Lys Glu 260 265 270 Arg Lys Thr Ser Thr Gly Ser Ser Gly Pro Met Glu Asp Ser Asp Gly 275 280 285 Cys Tyr Leu Gln Lys Ser Arg His Pro Arg Lys Leu Glu Leu Arg Gln 290 295 300 Leu Ser Pro Ser Ser Ser Gly Ser Asn Arg Ile Asn Arg Ile Arg Ser 305 310 315 320 Ser Ser Ser Thr Ala Asn Leu Met Ala Lys Lys Arg Val Ile Arg Met 325 330 335 Leu Ile Val Ile Val Val Leu Phe Phe Leu Cys Trp Met Pro Ile Phe 340 345 350 Ser Ala Asn Ala Trp Arg Ala Tyr Asp Thr Val Ser Ala Glu Arg His 355 360 365 Leu Ser Gly Thr Pro Ile Ser Phe Ile Leu Leu Leu Ser Tyr Thr Ser 370 375 380 Ser Cys Val Asn Pro Ile Ile Tyr Cys Phe Met Asn Lys Arg Phe Arg 385 390 395 400 Leu Gly Phe Met Ala Thr Phe Pro Cys Cys Pro Asn Pro Gly Thr Pro 405 410 415 Gly Val Arg Gly Glu Met Gly Glu Glu Glu Glu Gly Arg Thr Thr Gly 420 425 430 Ala Ser Leu Ser Arg Tyr Ser Tyr Ser His Met Ser Thr Ser Ala Pro 435 440 445 Pro Pro 450 2015 base pairs nucleic acid double linear guinea pig gallbladder and pancreas CCKB CDS 13..1374 25 CTCGGAGGGG CC ATG GAG CTG CTC AAG CTG AAC CGG AGC CTC CAG GGA 48 Met Glu Leu Leu Lys Leu Asn Arg Ser Leu Gln Gly 1 5 10 CCC GGG CCT GGG CCG GGG GCT CCC CTG TGC CGC CCG GCT GGC CCG CTT 96 Pro Gly Pro Gly Pro Gly Ala Pro Leu Cys Arg Pro Ala Gly Pro Leu 15 20 25 CTC AAC AGC AGC GGT GCA GGC AAC GTC AGC TGC GAA ACC CCT CGC ATC 144 Leu Asn Ser Ser Gly Ala Gly Asn Val Ser Cys Glu Thr Pro Arg Ile 30 35 40 CGA GGC GCC GGG ACG AGA GAA TTG GAG CTG GCC ATC AGA GTC ACC CTT 192 Arg Gly Ala Gly Thr Arg Glu Leu Glu Leu Ala Ile Arg Val Thr Leu 45 50 55 60 TAC GCA GTG ATC TTT CTG ATG AGC GTT GGA GGA AAT GTG CTC ATC ATT 240 Tyr Ala Val Ile Phe Leu Met Ser Val Gly Gly Asn Val Leu Ile Ile 65 70 75 GTG GTC CTG GGA CTG AGC CGC CGC CTG AGA ACT GTG ACC AAT GCT TTC 288 Val Val Leu Gly Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe 80 85 90 CTG CTC TCC CTG GCA GTC AGT GAC CTC CTG CTG GCT GTG GCT TGC ATG 336 Leu Leu Ser Leu Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met 95 100 105 CCC TTC ACA CTC CTG CCC AAT CTT ATG GGC ACA TTC ATC TTT GGC ACC 384 Pro Phe Thr Leu Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr 110 115 120 GTC ATC TGC AAG GCT GTT TCC TAC CTC ATG GGG GTG TCT GTG AGC GTG 432 Val Ile Cys Lys Ala Val Ser Tyr Leu Met Gly Val Ser Val Ser Val 125 130 135 140 TCC ACG CTC AGC CTT GTG GCC ATC GCC CTG GAG CGG TAC AGC GCC ATC 480 Ser Thr Leu Ser Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile 145 150 155 TGC CGA CCA CTG CAG GCT CGA GTG TGG CAG ACC CGC TCC CAC GCA GCT 528 Cys Arg Pro Leu Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala 160 165 170 CGC GTG ATT TTA GCC ACT TGG CTG CTG TCC GGA TTG CTC ATG GTC CCC 576 Arg Val Ile Leu Ala Thr Trp Leu Leu Ser Gly Leu Leu Met Val Pro 175 180 185 TAC CCT GTG TAC ACT GCT GTG CAG CCG GTA GGG CCT CGT GTG CTG CAG 624 Tyr Pro Val Tyr Thr Ala Val Gln Pro Val Gly Pro Arg Val Leu Gln 190 195 200 TGC GTG CAT CGC TGG CCC AAC GCA CGG GTC CGC CAG ACC TGG TCA GTA 672 Cys Val His Arg Trp Pro Asn Ala Arg Val Arg Gln Thr Trp Ser Val 205 210 215 220 CTG CTG CTC CTG CTC TTG TTC TTC GTC CCC GGA GTG GTT ATG GCA GTG 720 Leu Leu Leu Leu Leu Leu Phe Phe Val Pro Gly Val Val Met Ala Val 225 230 235 GCC TAC GGG CTC ATC TCC CGC GAG CTC TAC TTA GGG CTT CGC TTT GAC 768 Ala Tyr Gly Leu Ile Ser Arg Glu Leu Tyr Leu Gly Leu Arg Phe Asp 240 245 250 GGT GAC GCC GAC AGT GAG AGC CAG AGC AGG GTC CGA GGC CCG GGA GGT 816 Gly Asp Ala Asp Ser Glu Ser Gln Ser Arg Val Arg Gly Pro Gly Gly 255 260 265 CTG TCC GGT TCC GCG CCA GGT CCT GCT CAC CAG AAT GGG CGT TGC CGG 864 Leu Ser Gly Ser Ala Pro Gly Pro Ala His Gln Asn Gly Arg Cys Arg 270 275 280 CCT GAA TCT GGC CTG TCA GGC GAG GAC AGC GAC GGC TGC TAT GTG CAA 912 Pro Glu Ser Gly Leu Ser Gly Glu Asp Ser Asp Gly Cys Tyr Val Gln 285 290 295 300 CTG CCA CGG TCT CGG CCG GCC CTG GAG CTG TCG GCC CTG GCG GCG TCC 960 Leu Pro Arg Ser Arg Pro Ala Leu Glu Leu Ser Ala Leu Ala Ala Ser 305 310 315 ACC CCT GCA CCA GGA CCT GGC CCC CGG CCC ACC CAG GCC AAG CTG CTG 1008 Thr Pro Ala Pro Gly Pro Gly Pro Arg Pro Thr Gln Ala Lys Leu Leu 320 325 330 GCT AAG AAG CGC GTG GTG CGG ATG TTG CTG GTC ATC GTT GTG CTC TTT 1056 Ala Lys Lys Arg Val Val Arg Met Leu Leu Val Ile Val Val Leu Phe 335 340 345 TTC CTG TGT TGG TTG CCG GTG TAC AGC GCC AAC ACG TGG CGT GCC TTC 1104 Phe Leu Cys Trp Leu Pro Val Tyr Ser Ala Asn Thr Trp Arg Ala Phe 350 355 360 GAC GGC CCG GGT GCG CAT CGG GCC CTC TCG GGA GCT CCC ATC TCT TTC 1152 Asp Gly Pro Gly Ala His Arg Ala Leu Ser Gly Ala Pro Ile Ser Phe 365 370 375 380 ATC CAT TTG CTG AGC TAC GCC TCC GCC TGT GTC AAC CCA CTG GTC TAC 1200 Ile His Leu Leu Ser Tyr Ala Ser Ala Cys Val Asn Pro Leu Val Tyr 385 390 395 TGC TTC ATG CAC CGT CCG TTT CGC CAG GCC TGC CTG GAC ACT TGC GCC 1248 Cys Phe Met His Arg Pro Phe Arg Gln Ala Cys Leu Asp Thr Cys Ala 400 405 410 CGC TGC TGC CCT AGG CCT CCT CGA GCT CGT CCC AGG CCT CTC CCA GAG 1296 Arg Cys Cys Pro Arg Pro Pro Arg Ala Arg Pro Arg Pro Leu Pro Glu 415 420 425 GAG GAC CCT CCC ACC CCC TCC ATT CGT TCG CTG TCC AGG CTG AGC TAC 1344 Glu Asp Pro Pro Thr Pro Ser Ile Arg Ser Leu Ser Arg Leu Ser Tyr 430 435 440 ACC ACC ATC AGC ACG CTG GGG CCC GGC TGATGGGGGT GGTGGGGGCG 1391 Thr Thr Ile Ser Thr Leu Gly Pro Gly 445 450 CTGAGGCAGC ACAGGCATCC TGTAAGCACA AATACATCCA GACACACAAG AAACACAAAC 1451 CACACTTGAC AGAGAGACTA ACACTCAACA GCATCGACTA ACCCAACACT CAGGAAACGG 1511 TGGCATAGTA CACACACACA CACACACACC AGAGCTTTAC ACAGAAAGGA GGCTCCCTGA 1571 GGGCCTTCCT AGAGACAGGG CACTGATCTT GACAGGCAAA CATAGCATCC TTAGCAGCAT 1631 CCTTATGCAC TGGGAACTCT GACAGCTGAC CGGTCCTCAT GCCCACATGC ATTAATCACA 1691 CTGATTCTCT AAGGGCAGCA GACCGTGGCA CAGGACTGAT TTGGGTTATT CCAGGCTGTC 1751 TTTAGTTTGA CATCACAAGA CACTTCTCCC CACCAGCACT GCCCCTACAA CAGGCCTGAT 1811 ACCTTCCTGA CCAACAGGCT CTTTAGGACT AAAAACTCTC TCTTCGTCCC TTTCCAGTTA 1871 AGGACTGCAG CCCTGCCCCC TCATCTTCAC CAGACCTCTT CAAAACACAA TAAATGACTT 1931 GCTCTCAAAA AAAAAAAAAA AAAAAAAAGC GGNNGCAGAA TTCGAGCTCG GTACCCGGGG 1991 ATCCTCTAGA GTCGACCTGC AGGC 2015 453 amino acids amino acid linear protein 26 Met Glu Leu Leu Lys Leu Asn Arg Ser Leu Gln Gly Pro Gly Pro Gly 1 5 10 15 Pro Gly Ala Pro Leu Cys Arg Pro Ala Gly Pro Leu Leu Asn Ser Ser 20 25 30 Gly Ala Gly Asn Val Ser Cys Glu Thr Pro Arg Ile Arg Gly Ala Gly 35 40 45 Thr Arg Glu Leu Glu Leu Ala Ile Arg Val Thr Leu Tyr Ala Val Ile 50 55 60 Phe Leu Met Ser Val Gly Gly Asn Val Leu Ile Ile Val Val Leu Gly 65 70 75 80 Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe Leu Leu Ser Leu 85 90 95 Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met Pro Phe Thr Leu 100 105 110 Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr Val Ile Cys Lys 115 120 125 Ala Val Ser Tyr Leu Met Gly Val Ser Val Ser Val Ser Thr Leu Ser 130 135 140 Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile Cys Arg Pro Leu 145 150 155 160 Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala Arg Val Ile Leu 165 170 175 Ala Thr Trp Leu Leu Ser Gly Leu Leu Met Val Pro Tyr Pro Val Tyr 180 185 190 Thr Ala Val Gln Pro Val Gly Pro Arg Val Leu Gln Cys Val His Arg 195 200 205 Trp Pro Asn Ala Arg Val Arg Gln Thr Trp Ser Val Leu Leu Leu Leu 210 215 220 Leu Leu Phe Phe Val Pro Gly Val Val Met Ala Val Ala Tyr Gly Leu 225 230 235 240 Ile Ser Arg Glu Leu Tyr Leu Gly Leu Arg Phe Asp Gly Asp Ala Asp 245 250 255 Ser Glu Ser Gln Ser Arg Val Arg Gly Pro Gly Gly Leu Ser Gly Ser 260 265 270 Ala Pro Gly Pro Ala His Gln Asn Gly Arg Cys Arg Pro Glu Ser Gly 275 280 285 Leu Ser Gly Glu Asp Ser Asp Gly Cys Tyr Val Gln Leu Pro Arg Ser 290 295 300 Arg Pro Ala Leu Glu Leu Ser Ala Leu Ala Ala Ser Thr Pro Ala Pro 305 310 315 320 Gly Pro Gly Pro Arg Pro Thr Gln Ala Lys Leu Leu Ala Lys Lys Arg 325 330 335 Val Val Arg Met Leu Leu Val Ile Val Val Leu Phe Phe Leu Cys Trp 340 345 350 Leu Pro Val Tyr Ser Ala Asn Thr Trp Arg Ala Phe Asp Gly Pro Gly 355 360 365 Ala His Arg Ala Leu Ser Gly Ala Pro Ile Ser Phe Ile His Leu Leu 370 375 380 Ser Tyr Ala Ser Ala Cys Val Asn Pro Leu Val Tyr Cys Phe Met His 385 390 395 400 Arg Pro Phe Arg Gln Ala Cys Leu Asp Thr Cys Ala Arg Cys Cys Pro 405 410 415 Arg Pro Pro Arg Ala Arg Pro Arg Pro Leu Pro Glu Glu Asp Pro Pro 420 425 430 Thr Pro Ser Ile Arg Ser Leu Ser Arg Leu Ser Tyr Thr Thr Ile Ser 435 440 445 Thr Leu Gly Pro Gly 450 453 amino acids amino acid linear canine gastrin receptor 27 Met Glu Leu Leu Lys Leu Asn Arg Ser Ala Gln Gly Ser Gly Ala Gly 1 5 10 15 Pro Gly Ala Ser Leu Cys Arg Ala Gly Gly Ala Leu Leu Asn Ser Ser 20 25 30 Gly Ala Gly Asn Leu Ser Cys Glu Pro Pro Arg Leu Arg Gly Ala Gly 35 40 45 Thr Arg Glu Leu Glu Leu Ala Ile Arg Val Thr Leu Tyr Ala Val Ile 50 55 60 Phe Leu Met Ser Val Gly Gly Asn Val Leu Ile Ile Val Val Leu Gly 65 70 75 80 Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe Leu Leu Ser Leu 85 90 95 Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met Pro Phe Thr Leu 100 105 110 Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr Val Val Cys Lys 115 120 125 Ala Val Ser Tyr Leu Met Gly Val Ser Val Ser Val Ser Thr Leu Ser 130 135 140 Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile Cys Arg Pro Leu 145 150 155 160 Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala Arg Val Ile Ile 165 170 175 Ala Thr Trp Met Leu Ser Gly Leu Leu Met Val Pro Tyr Pro Val Tyr 180 185 190 Thr Ala Val Gln Pro Ala Gly Gly Ala Arg Ala Leu Gln Cys Val His 195 200 205 Arg Trp Pro Ser Ala Arg Val Arg Gln Thr Trp Ser Val Leu Leu Leu 210 215 220 Leu Leu Leu Phe Phe Val Pro Gly Val Val Met Ala Val Ala Tyr Gly 225 230 235 240 Leu Ile Ser Arg Glu Leu Tyr Leu Gly Leu Arg Phe Asp Glu Asp Ser 245 250 255 Asp Ser Glu Ser Arg Val Arg Ser Gln Gly Gly Leu Arg Gly Gly Ala 260 265 270 Gly Pro Gly Pro Ala Pro Pro Asn Gly Ser Cys Arg Pro Glu Gly Gly 275 280 285 Leu Ala Gly Glu Asp Gly Asp Gly Cys Tyr Val Gln Leu Pro Arg Ser 290 295 300 Arg Gln Thr Leu Glu Leu Ser Ala Leu Thr Ala Pro Thr Pro Gly Pro 305 310 315 320 Gly Gly Gly Pro Arg Pro Tyr Gln Ala Lys Leu Leu Ala Lys Lys Arg 325 330 335 Val Val Arg Met Leu Leu Val Ile Val Val Leu Phe Phe Leu Cys Trp 340 345 350 Leu Pro Leu Tyr Ser Ala Asn Thr Trp Arg Ala Phe Asp Ser Ser Gly 355 360 365 Ala His Arg Ala Leu Ser Gly Ala Pro Ile Ser Phe Ile His Leu Leu 370 375 380 Ser Tyr Ala Ser Ala Cys Val Asn Pro Leu Val Tyr Cys Phe Met His 385 390 395 400 Arg Arg Phe Arg Gln Ala Cys Leu Glu Thr Cys Ala Arg Cys Cys Pro 405 410 415 Arg Pro Pro Arg Ala Arg Pro Arg Pro Leu Pro Asp Glu Asp Pro Pro 420 425 430 Thr Pro Ser Ile Ala Ser Leu Ser Arg Leu Ser Tyr Thr Thr Ile Ser 435 440 445 Thr Leu Gly Pro Gly 450 1969 base pairs nucleic acid double linear cDNA human CCKB receptor CDS 1..1344 28 ATG GAG CTG CTC AAG CTG AAC CGG AAC GTG CAG GGA ACC GGA CCC GGG 48 Met Glu Leu Leu Lys Leu Asn Arg Asn Val Gln Gly Thr Gly Pro Gly 1 5 10 15 CCG GGG GCT TCC CTG TGC CGC CCG GGG GCG CCT CTC CTC AAC AGC AGC 96 Pro Gly Ala Ser Leu Cys Arg Pro Gly Ala Pro Leu Leu Asn Ser Ser 20 25 30 AGT GTG GGC AAC CTC AGC TGC GAG CCC CCT CGC ATT CGC GGA GCC GGG 144 Ser Val Gly Asn Leu Ser Cys Glu Pro Pro Arg Ile Arg Gly Ala Gly 35 40 45 ACA CGA GAA TTG GAG CTG GCC ATT AGA ATC ACT CTT TAC GCA GTG ATC 192 Thr Arg Glu Leu Glu Leu Ala Ile Arg Ile Thr Leu Tyr Ala Val Ile 50 55 60 TTC CTG ATG AGC GTT GGA GGA AAT ATG CTC ATC ATC GTG GTC CTG GGA 240 Phe Leu Met Ser Val Gly Gly Asn Met Leu Ile Ile Val Val Leu Gly 65 70 75 80 CTG AGC CGC CGC CTG AGG ACT GTC ACC AAT GCC TTC CTC CTC TCA CTG 288 Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe Leu Leu Ser Leu 85 90 95 GCA GTC AGC GAC CTC CTG CTG GCT GTG GCT TGC ATG CCC TTC ACC CTC 336 Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met Pro Phe Thr Leu 100 105 110 CTG CCC AAT CTC ATG GGC ACA TTC ATC TTT GGC ACC GTC ATC TGC AAG 384 Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr Val Ile Cys Lys 115 120 125 GCG GTT TCC TAC CTC ATG GGG GTG TCT GTG AGT GTG TCC ACG CTA AGC 432 Ala Val Ser Tyr Leu Met Gly Val Ser Val Ser Val Ser Thr Leu Ser 130 135 140 CTC GTG GCC ATC GCA CTG GAG CGG TAC AGC GCC ATC TGC CGA CCA CTG 480 Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile Cys Arg Pro Leu 145 150 155 160 CAG GCA CGA GTG TGG CAG ACG CGC TCC CAC GCG GCT CGC GTG ATT GTA 528 Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala Arg Val Ile Val 165 170 175 GCC ACG TGG CTG CTG TCC GGA CTA CTC ATG GTG CCC TAC CCC GTG TAC 576 Ala Thr Trp Leu Leu Ser Gly Leu Leu Met Val Pro Tyr Pro Val Tyr 180 185 190 ACT GTC GTG CAA CCA GTG GGG CCT CGT GTG CTG CAG TGC GTG CAT CGC 624 Thr Val Val Gln Pro Val Gly Pro Arg Val Leu Gln Cys Val His Arg 195 200 205 TGG CCC AGT GCG CGG GTC CGC CAG ACC TGG TCC GTA CTG CTG CTT CTG 672 Trp Pro Ser Ala Arg Val Arg Gln Thr Trp Ser Val Leu Leu Leu Leu 210 215 220 CTC TTG TTC TTC ATC CCG AGT GTG GTT ATG GCC GTG GCC TAC GGG CTT 720 Leu Leu Phe Phe Ile Pro Ser Val Val Met Ala Val Ala Tyr Gly Leu 225 230 235 240 ATC TCT CGC GAG CTC TAC TTA GGG CTT CGC TTT GAC GGC GAC AGT GAC 768 Ile Ser Arg Glu Leu Tyr Leu Gly Leu Arg Phe Asp Gly Asp Ser Asp 245 250 255 AGC GAC AGC CAA AGC AGG GTC CGA AAC CAA GGC GGG CTG CCA GGG GCT 816 Ser Asp Ser Gln Ser Arg Val Arg Asn Gln Gly Gly Leu Pro Gly Ala 260 265 270 GTT CAC CAG AAC GGG CGT TGC CGG CCT GAG ACT GGC GCG GTT GGC GAA 864 Val His Gln Asn Gly Arg Cys Arg Pro Glu Thr Gly Ala Val Gly Glu 275 280 285 GAC AGC GAT GGC TGC TAC GTG CAA CTT CCA CGT TCC CGG CCT GCC CTG 912 Asp Ser Asp Gly Cys Tyr Val Gln Leu Pro Arg Ser Arg Pro Ala Leu 290 295 300 GAG CTG ACG GCG CTG ACG GCT CCA GGG CCG GGA TCC GGC TCC CGG CCC 960 Glu Leu Thr Ala Leu Thr Ala Pro Gly Pro Gly Ser Gly Ser Arg Pro 305 310 315 320 ACC CAG GCC AAG CTG CTG GCT AAG AAG CGC GTG GTG CGA ATG TTG CTG 1008 Thr Gln Ala Lys Leu Leu Ala Lys Lys Arg Val Val Arg Met Leu Leu 325 330 335 GTG ATC GTT GTG CTT TTT TTT CTG TGT TGG TTG CCA GTT TAT AGT GCC 1056 Val Ile Val Val Leu Phe Phe Leu Cys Trp Leu Pro Val Tyr Ser Ala 340 345 350 AAC ACG TGG CGC GCC TTT GAT GGC CCG GGT GCA CAC CGA GCA CTC TCG 1104 Asn Thr Trp Arg Ala Phe Asp Gly Pro Gly Ala His Arg Ala Leu Ser 355 360 365 GGT GCT CCT ATC TCC TTC ATT CAC TTG CTG AGC TAC GCC TCG GCC TGT 1152 Gly Ala Pro Ile Ser Phe Ile His Leu Leu Ser Tyr Ala Ser Ala Cys 370 375 380 GTC AAC CCC CTG GTC TAC TGC TTC ATG CAC CGT CGC TTT CGC CAG GCC 1200 Val Asn Pro Leu Val Tyr Cys Phe Met His Arg Arg Phe Arg Gln Ala 385 390 395 400 TGC CTG GAA ACT TGC GCT CGC TGC TGC CCC CGG CCT CCA CGA GCT CGC 1248 Cys Leu Glu Thr Cys Ala Arg Cys Cys Pro Arg Pro Pro Arg Ala Arg 405 410 415 CCC AGG GCT CTT CCC GAT GAG GAC CCT CCC ACT CCC TCC ATT GCT TCG 1296 Pro Arg Ala Leu Pro Asp Glu Asp Pro Pro Thr Pro Ser Ile Ala Ser 420 425 430 CTG TCC AGG CTT AGC TAC ACC ACC ATC AGC ACA CTG GGC CCT GGC TGAGGAGT1351 Leu Ser Arg Leu Ser Tyr Thr Thr Ile Ser Thr Leu Gly Pro Gly 435 440 445 AGGGGCCGTG GGGGTTGAGG CAGGGCAAAT GACATGCACT GACCCTTCCA GACATAGAAA 1411 ACACAAACCA CAACTGACAC AGGAAACCAA CACCCAAAGC ATGGACTAAC CCCAACGACA 1471 GGAAAAGGTA GCTTACCTGA CACAAGAGGA ATAAGAATGG AGCAGTACAT GGGAAAGGAG 1531 GCATGCCTCT GATATGGGAC TGAGCCTGGC CCATAGAAAC ATGACACTGA CCTTGGAGAG 1591 ACACAGCGTC CCTAGCAGTG AACTATTTCT ACACAGTGGG AACTCTGACA AGGGCTGACC 1651 TGCCTCTCAC ACACATAGAT TAATGGCACT GATTGTTTTA GAGACTATGG AGCCTGGCAC 1711 AGGACTGACT CTGGGATGCT CCTAGTTTGA CCTCACAGTG ACCCTTCCCA ATCAGCACTG 1771 AAAATACCAT CAGGCCTAAT CTCATACCTC TGACCAACAG GCTGTTCTGC ACTGAAAAGG 1831 TTCTTCATCC CTTTCCAGTT AAGGACCGTG GCCCTGCCCT CTCCTTCCTT CCCAAACTGT 1891 TCAAGAAATA ATAAATTGTT TGGCTTCCTC CTGAAAAAAA AAAAAAAAAA AAAAAAAAAA 1951 AAAAAAAAAA GGAATTCC 1969 447 amino acids amino acid linear protein 29 Met Glu Leu Leu Lys Leu Asn Arg Asn Val Gln Gly Thr Gly Pro Gly 1 5 10 15 Pro Gly Ala Ser Leu Cys Arg Pro Gly Ala Pro Leu Leu Asn Ser Ser 20 25 30 Ser Val Gly Asn Leu Ser Cys Glu Pro Pro Arg Ile Arg Gly Ala Gly 35 40 45 Thr Arg Glu Leu Glu Leu Ala Ile Arg Ile Thr Leu Tyr Ala Val Ile 50 55 60 Phe Leu Met Ser Val Gly Gly Asn Met Leu Ile Ile Val Val Leu Gly 65 70 75 80 Leu Ser Arg Arg Leu Arg Thr Val Thr Asn Ala Phe Leu Leu Ser Leu 85 90 95 Ala Val Ser Asp Leu Leu Leu Ala Val Ala Cys Met Pro Phe Thr Leu 100 105 110 Leu Pro Asn Leu Met Gly Thr Phe Ile Phe Gly Thr Val Ile Cys Lys 115 120 125 Ala Val Ser Tyr Leu Met Gly Val Ser Val Ser Val Ser Thr Leu Ser 130 135 140 Leu Val Ala Ile Ala Leu Glu Arg Tyr Ser Ala Ile Cys Arg Pro Leu 145 150 155 160 Gln Ala Arg Val Trp Gln Thr Arg Ser His Ala Ala Arg Val Ile Val 165 170 175 Ala Thr Trp Leu Leu Ser Gly Leu Leu Met Val Pro Tyr Pro Val Tyr 180 185 190 Thr Val Val Gln Pro Val Gly Pro Arg Val Leu Gln Cys Val His Arg 195 200 205 Trp Pro Ser Ala Arg Val Arg Gln Thr Trp Ser Val Leu Leu Leu Leu 210 215 220 Leu Leu Phe Phe Ile Pro Ser Val Val Met Ala Val Ala Tyr Gly Leu 225 230 235 240 Ile Ser Arg Glu Leu Tyr Leu Gly Leu Arg Phe Asp Gly Asp Ser Asp 245 250 255 Ser Asp Ser Gln Ser Arg Val Arg Asn Gln Gly Gly Leu Pro Gly Ala 260 265 270 Val His Gln Asn Gly Arg Cys Arg Pro Glu Thr Gly Ala Val Gly Glu 275 280 285 Asp Ser Asp Gly Cys Tyr Val Gln Leu Pro Arg Ser Arg Pro Ala Leu 290 295 300 Glu Leu Thr Ala Leu Thr Ala Pro Gly Pro Gly Ser Gly Ser Arg Pro 305 310 315 320 Thr Gln Ala Lys Leu Leu Ala Lys Lys Arg Val Val Arg Met Leu Leu 325 330 335 Val Ile Val Val Leu Phe Phe Leu Cys Trp Leu Pro Val Tyr Ser Ala 340 345 350 Asn Thr Trp Arg Ala Phe Asp Gly Pro Gly Ala His Arg Ala Leu Ser 355 360 365 Gly Ala Pro Ile Ser Phe Ile His Leu Leu Ser Tyr Ala Ser Ala Cys 370 375 380 Val Asn Pro Leu Val Tyr Cys Phe Met His Arg Arg Phe Arg Gln Ala 385 390 395 400 Cys Leu Glu Thr Cys Ala Arg Cys Cys Pro Arg Pro Pro Arg Ala Arg 405 410 415 Pro Arg Ala Leu Pro Asp Glu Asp Pro Pro Thr Pro Ser Ile Ala Ser 420 425 430 Leu Ser Arg Leu Ser Tyr Thr Thr Ile Ser Thr Leu Gly Pro Gly 435 440 445 1686 base pairs nucleic acid double linear Human CCKAR CDS 154..1440 30 GGAATGGCTG AAAAAGCCCA CACCTGGAAA TCACTCCCTC CCTGCTCCTC CACGGCAGGT 60 TGCATCTGCG AGACGCTTCG GTCATTAGAG GAATGAGCCG GGAGTGAGCA ATTCACCAGC 120 TCTCCAGCAC TTGGTGGAAA GCAGCAGGCA AGG ATG GAT GTG GTT GAC AGC CTT 174 Met Asp Val Val Asp Ser Leu 1 5 CTT GTG AAT GGA AGC AAC ATC ACT CCT CCC TGT GAA CTC GGG CTC GAA 222 Leu Val Asn Gly Ser Asn Ile Thr Pro Pro Cys Glu Leu Gly Leu Glu 10 15 20 AAT GAG ACG CTT TTC TGC TTG GAT CAG CCC CGT CCT TCC AAA GAG TGG 270 Asn Glu Thr Leu Phe Cys Leu Asp Gln Pro Arg Pro Ser Lys Glu Trp 25 30 35 CAG CCA GCG GTG CAG ATT CTC TTG TAC TCC TTG ATA TTC CTG CTC AGC 318 Gln Pro Ala Val Gln Ile Leu Leu Tyr Ser Leu Ile Phe Leu Leu Ser 40 45 50 55 GTG CTG GGA AAC ACG CTG GTC ATC ACC GTG CTG ATT CGG AAC AAG CGG 366 Val Leu Gly Asn Thr Leu Val Ile Thr Val Leu Ile Arg Asn Lys Arg 60 65 70 ATG CGG ACG GTC ACC AAC ATC TTC CTC CTC TCC CTG GCT GTC AGC GAC 414 Met Arg Thr Val Thr Asn Ile Phe Leu Leu Ser Leu Ala Val Ser Asp 75 80 85 CTC ATG CTC TGT CTC TTC TGC ATG CCG TTC AAC CTC ATC CCC AAT CTG 462 Leu Met Leu Cys Leu Phe Cys Met Pro Phe Asn Leu Ile Pro Asn Leu 90 95 100 CTC AAG GAT TTC ATC TTC GGG AGC GCC GTT TGC AAG ACC ACC ACC TAC 510 Leu Lys Asp Phe Ile Phe Gly Ser Ala Val Cys Lys Thr Thr Thr Tyr 105 110 115 TTC ATG GGC ACC TCT GTG AGT GTA TCT ACC TTT AAT CTG GTA GCC ATA 558 Phe Met Gly Thr Ser Val Ser Val Ser Thr Phe Asn Leu Val Ala Ile 120 125 130 135 TCT CTA GAG AGA TAT GGT GCG ATT TGC AAA CCC TTA CAG TCC CGG GTC 606 Ser Leu Glu Arg Tyr Gly Ala Ile Cys Lys Pro Leu Gln Ser Arg Val 140 145 150 TGG CAG ACA AAA TCC CAT GCT TTG AAG GTG ATT GCT GCT ACC TGG TGC 654 Trp Gln Thr Lys Ser His Ala Leu Lys Val Ile Ala Ala Thr Trp Cys 155 160 165 CTT TCC TTT ACC ATC ATG ACT CCG TAC CCC ATT TAT AGC AAC TTG GTG 702 Leu Ser Phe Thr Ile Met Thr Pro Tyr Pro Ile Tyr Ser Asn Leu Val 170 175 180 CCT TTT ACC AAA AAT AAC AAC CAG ACC GCG AAT ATG TGC CGC TTT CTA 750 Pro Phe Thr Lys Asn Asn Asn Gln Thr Ala Asn Met Cys Arg Phe Leu 185 190 195 CTG CCA AAT GAT GTT ATG CAG CAG TCC TGG CAC ACA TTC CTG TTA CTC 798 Leu Pro Asn Asp Val Met Gln Gln Ser Trp His Thr Phe Leu Leu Leu 200 205 210 215 ATC CTC TTT CTT ATT CCT GGA ATT GTG ATG ATG GTG GCA TAT GGA TTA 846 Ile Leu Phe Leu Ile Pro Gly Ile Val Met Met Val Ala Tyr Gly Leu 220 225 230 ATC TCT TTG GAA CTC TAC CAG GGA ATA AAA TTT GAG GCT AGC CAG AAG 894 Ile Ser Leu Glu Leu Tyr Gln Gly Ile Lys Phe Glu Ala Ser Gln Lys 235 240 245 AAG TCT GCT AAA GAA AGG AAA CCT AGC ACC ACC AGC AGC GGC AAA TAT 942 Lys Ser Ala Lys Glu Arg Lys Pro Ser Thr Thr Ser Ser Gly Lys Tyr 250 255 260 GAG GAC AGC GAT GGG TGT TAC CTG CAA AAG ACC AGG CCC CCG AGG AAG 990 Glu Asp Ser Asp Gly Cys Tyr Leu Gln Lys Thr Arg Pro Pro Arg Lys 265 270 275 CTG GAG CTC CGG CAG CTG TCC ACC GGC AGC AGC AGC AGG GCC AAC CGC 1038 Leu Glu Leu Arg Gln Leu Ser Thr Gly Ser Ser Ser Arg Ala Asn Arg 280 285 290 295 ATC CGG AGT AAC AGC TCC GCA GCC AAC CTG ATG GCC AAG AAA AGG GTG 1086 Ile Arg Ser Asn Ser Ser Ala Ala Asn Leu Met Ala Lys Lys Arg Val 300 305 310 ATC CGC ATG CTC ATC GTC ATC GTG GTC CTC TTC TTC CTG TGC TGG ATG 1134 Ile Arg Met Leu Ile Val Ile Val Val Leu Phe Phe Leu Cys Trp Met 315 320 325 CCC ATC TTC AGC GCC AAC GCC TGG CGG GCC TAC GAC ACC GCC TCC GCA 1182 Pro Ile Phe Ser Ala Asn Ala Trp Arg Ala Tyr Asp Thr Ala Ser Ala 330 335 340 GAG CGC CGC CTC TCA GGA ACC CCC ATT TCC TTC ATC CTC CTC CTG TCC 1230 Glu Arg Arg Leu Ser Gly Thr Pro Ile Ser Phe Ile Leu Leu Leu Ser 345 350 355 TAC ACC TCC TCC TGC GTC AAC CCC ATC ATC TAC TGC TTC ATG AAC AAA 1278 Tyr Thr Ser Ser Cys Val Asn Pro Ile Ile Tyr Cys Phe Met Asn Lys 360 365 370 375 CGC TTC CGC CTC GGC TTC ATG GCC ACC TTC CCC TGC TGC CCC AAT CCT 1326 Arg Phe Arg Leu Gly Phe Met Ala Thr Phe Pro Cys Cys Pro Asn Pro 380 385 390 GGT CCC CCA GGG GCG AGG GGA GAG GTG GGG GAG GAG GAG GAA GGC GGG 1374 Gly Pro Pro Gly Ala Arg Gly Glu Val Gly Glu Glu Glu Glu Gly Gly 395 400 405 ACC ACA GGA GCC TCT CTG TCC AGG TTC TCG TAC AGC CAT ATG AGT GCC 1422 Thr Thr Gly Ala Ser Leu Ser Arg Phe Ser Tyr Ser His Met Ser Ala 410 415 420 TCG GTG CCA CCC CAG TGAGATGTCC CCTGACCCTC CACCGCAGAA GGAAGGCAGG 1477 Ser Val Pro Pro Gln 425 GAGGAGGCAG AGAAGAAAGA ACGGAAGAAG AGATCAGGAA GAGAAGGAGC AGAGCAGAGC 1537 TGATGGAGAA GGAAGGCTCC ATCTCCAGTG GGAACTCTTC AAGGTCTCTT TTCATCCTTC 1597 ATCTGATTCC AGAGCACTGC TCCAGTGGGG CCATGATTGG TTTCTAGGCA GTTCAAAGCA 1657 GGATATGTTA AGTAACACTC AACCATCAG 1686 428 amino acids amino acid linear protein 31 Met Asp Val Val Asp Ser Leu Leu Val Asn Gly Ser Asn Ile Thr Pro 1 5 10 15 Pro Cys Glu Leu Gly Leu Glu Asn Glu Thr Leu Phe Cys Leu Asp Gln 20 25 30 Pro Arg Pro Ser Lys Glu Trp Gln Pro Ala Val Gln Ile Leu Leu Tyr 35 40 45 Ser Leu Ile Phe Leu Leu Ser Val Leu Gly Asn Thr Leu Val Ile Thr 50 55 60 Val Leu Ile Arg Asn Lys Arg Met Arg Thr Val Thr Asn Ile Phe Leu 65 70 75 80 Leu Ser Leu Ala Val Ser Asp Leu Met Leu Cys Leu Phe Cys Met Pro 85 90 95 Phe Asn Leu Ile Pro Asn Leu Leu Lys Asp Phe Ile Phe Gly Ser Ala 100 105 110 Val Cys Lys Thr Thr Thr Tyr Phe Met Gly Thr Ser Val Ser Val Ser 115 120 125 Thr Phe Asn Leu Val Ala Ile Ser Leu Glu Arg Tyr Gly Ala Ile Cys 130 135 140 Lys Pro Leu Gln Ser Arg Val Trp Gln Thr Lys Ser His Ala Leu Lys 145 150 155 160 Val Ile Ala Ala Thr Trp Cys Leu Ser Phe Thr Ile Met Thr Pro Tyr 165 170 175 Pro Ile Tyr Ser Asn Leu Val Pro Phe Thr Lys Asn Asn Asn Gln Thr 180 185 190 Ala Asn Met Cys Arg Phe Leu Leu Pro Asn Asp Val Met Gln Gln Ser 195 200 205 Trp His Thr Phe Leu Leu Leu Ile Leu Phe Leu Ile Pro Gly Ile Val 210 215 220 Met Met Val Ala Tyr Gly Leu Ile Ser Leu Glu Leu Tyr Gln Gly Ile 225 230 235 240 Lys Phe Glu Ala Ser Gln Lys Lys Ser Ala Lys Glu Arg Lys Pro Ser 245 250 255 Thr Thr Ser Ser Gly Lys Tyr Glu Asp Ser Asp Gly Cys Tyr Leu Gln 260 265 270 Lys Thr Arg Pro Pro Arg Lys Leu Glu Leu Arg Gln Leu Ser Thr Gly 275 280 285 Ser Ser Ser Arg Ala Asn Arg Ile Arg Ser Asn Ser Ser Ala Ala Asn 290 295 300 Leu Met Ala Lys Lys Arg Val Ile Arg Met Leu Ile Val Ile Val Val 305 310 315 320 Leu Phe Phe Leu Cys Trp Met Pro Ile Phe Ser Ala Asn Ala Trp Arg 325 330 335 Ala Tyr Asp Thr Ala Ser Ala Glu Arg Arg Leu Ser Gly Thr Pro Ile 340 345 350 Ser Phe Ile Leu Leu Leu Ser Tyr Thr Ser Ser Cys Val Asn Pro Ile 355 360 365 Ile Tyr Cys Phe Met Asn Lys Arg Phe Arg Leu Gly Phe Met Ala Thr 370 375 380 Phe Pro Cys Cys Pro Asn Pro Gly Pro Pro Gly Ala Arg Gly Glu Val 385 390 395 400 Gly Glu Glu Glu Glu Gly Gly Thr Thr Gly Ala Ser Leu Ser Arg Phe 405 410 415 Ser Tyr Ser His Met Ser Ala Ser Val Pro Pro Gln 420 425 21 base pairs nucleic acid single linear 32 CGTTCTTTCT TCTCTGCCTC C 21 

What is claimed is:
 1. An isolated DNA molecule encoding a CCK receptor protein.
 2. An isolated DNA molecule according to claim 1, wherein said molecule comprises nucleotides 1 to 1341 of FIG. 12 (SEQ ID NO:28) or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting essentially of said nucleotides 1 to 1341 of FIG. 12 (SEQ ID NO:28).
 3. An isolated DNA molecule according to claim 1, comprising a first nucleotide sequence that consists essentially of (A) nucleotides 199 to 1485 of FIG. 1 (SEQ ID NO:13) or (B) a polynucleotide sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting essentially of nucleotides 199 to 1485 of FIG. 1 (SEQ ID NO:13).
 4. An isolated DNA molecule according to claim 3, wherein (i) said first nucleotide sequence consists essentially of nucleotides 199 to 1485 of FIG. 1 (SEQ ID NO:13) and (ii) said DNA molecule further comprises a second nucleotide sequence consisting essentially of nucleotides 154-198 of FIG. 1 (SEQ ID NO:13), said second nucleotide sequence being positioned immediately upstream of nucleotide 199 of said first nucleotide sequence.
 5. An isolated DNA molecule according to claim 1, wherein said molecule comprises nucleotides 136 to 1491 of FIG. 2 (SEQ ID NO:15) or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting essentially of said nucleotides 136 to
 1491. 6. A cell transformed with DNA molecule encoding a CCK receptor protein, where said cell expresses a heterologous polypeptide that possesses a biological activity characteristic of CCK receptor protein.
 7. The transformed cell according to claim 6, wherein said cell is a eukaryptic cell.
 8. The transformed cell according to claim 7, wherein said cell is a Xenopus oocyte.
 9. The transformed cell according to claim 7, wherein said cell is a COS, CHO cell or Swiss 3T3 cell.
 10. The transformed cell according to claim 6 wherein said cell is a prokaryotic cell.
 11. The transformed cell according to claim 6, wherein said cell is an insect cell.
 12. A method for purifying a cholecystokinin receptor comprising the steps of (a) solubilizing a biological preparation containing cholecystokinin receptor in 1% digitonin, (b) applying said solubilized receptor preparation to a cationic exchange resin, and purifying the eluate of said resin, (c) applying said purified eluate to an agarose-bound lectin, and (d) applying an eluate of step (c) to a cibacron blue sepharose column.
 13. A method according to claim 12, wherein said lectin is a wheat-germ agglutinin.
 14. A method according to claim 12, further comprising the step (e) of trace-labeling and subjecting product from step (d) to SDS-PAGE gel electrophoresis under reducing conditions to obtain purified receptor.
 15. CCK receptor protein of sequencable-grade purity.
 16. CCK receptor protein according to claim 15, said protein comprising the amino acid sequence shown in FIG. 12 (SEQ ID NO:29).
 17. CCK receptor protein according to claim 15, said protein comprising the amino acid sequence shown in FIG. 1 (SEQ ID NO:14).
 18. CCK receptor protein according to claim 15, said protein comprising the amino acid sequence 16-444 of FIG. 1 (SEQ ID NO:14).
 19. CCK receptor protein according to claim 15, said protein comprising the amino acid sequence shown in FIG. 2 (SEQ ID NO:16).
 20. An isolated DNA molecule according to claim 1, wherein said molecule comprises nucleotides 154-1437 of FIG. 13 or a DNA sequence which hybridizes under high stringency conditions to an oligonucleotide probe consisting essentially of said nucleotides 154-1437 of FIG.
 13. 21. CCK receptor protein according to claim 15, said protein comprising the amino acid sequence shown in FIG.
 13. 